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How to Wire a Switch off an Outlet [Full Guide]

How to Wire a Switch off an Outlet [Full Guide]

We all agree that electrical wiring can be a bit confusing for non-professionals. Added to that is it can be dangerous if it’s not done the right way. 

However, that doesn’t mean that you can’t do some basic wiring projects at your house. 

When it comes to adding a new switch in a location that is convenient for you, the best way to do it is by drawing power from the nearest outlet. 

It’s a simple process once you fully understand it. 

So, we created a complete guide on how to wire a switch off an outlet to guide you through the entire process. 

Let’s begin! 

The Basics of How to Wire a Light Switch and Outlet

Before jumping into the actual steps of wiring an outlet switch, it’s essential to understand the basics of the process first. 

If you’re not new to electrical wiring, you might want to skip this part.

Otherwise, pay attention to the details to make the process easier for you.

Identify Electrical Wires

One of the things you’ll need for wiring is a 12/2 Romex cable that contains three wires: black, ground, and white

The black wire, also known as the hot wire, carries electricity from the breaker panel to the outlet or switch. 

Meanwhile, the white wire acts as a drain. It sends unused electricity or power back to the breaker panel. 

Finally, we have the ground wire. It’s usually copper, but sometimes it comes in green. However, in our case, it’ll be copper. 

It acts as a sort of back-up, overflow drain in case the white wire ever fails.

So, it basically prevents the electricity from running through us should we ever come into contact with the insides of a live switch or outlet box. 

identifying electrical wires

Know the Paths of the Wires

So, to wire a light switch or an outlet, you need to run power from the breaker panel to the switch or the outlet.

You also need to run power from the switch to the light fixture. 

In the case of wiring a light switch to an outlet, our 12/2 cable should be running from the breaker panel to the outlet already (of course!). 

Then, we run another sheathed cable from the outlet to our switch.

We also need another cable from the switch to the lightbox. 

Don’t worry; this will make much more sense when we start with the actual steps of the process. 

How to Wire a Switch off an Existing Outlet?

When it comes to adding a light switch to an existing outlet, you’ll have to fish for wires behind drywall. 

It might sound hard in the beginning, but it’s actually relatively simple, and you can do it yourself. 

This process will take you about 20 to 30 minutes or maybe even less if you have experience with wiring. 

Here are the steps for wiring a light switch to an outlet:

Step One: Prepare for the Process

First things first, you need to make sure that you have all the tools you need:

  • Old work electrical box 
  • 12/2 Romex wire
  • Stud finder
  • Wire fish tape
  • Drywall saw
  • Level 
  • Cordless drill 
  • Utility knife 
  • Screwdriver 
  • Wire stripper
  • Electrician pliers
  • Wire staples
  • Wire nuts 
  • Twist grounding wire connector 
  • Voltage tester 
  • Electrical tape 

wiring process

Second, you need to make sure that the power is off on the outlet you’re working at. To do that, head to your panel box. 

Locate the circuit you’re working on and kick the breaker. Then, go to the outlet and double-check with a tester that there’s no power. 

Step Two: Locate Studs 

Make sure to go with your stud finder horizontally and vertically over the area where you want to add your new switch. This way, you can locate any studs or fire blocks. 

Once you figure out the appropriate position for your new switch, grab your electrical box and put it up in its designated location.

Then, trace its outline. Now comes the time for cutting the opening for the box. 

It’s best to start with drilling a ½ inch starter hole at one of the corners of the outline.

Then, with your drywall saw, cut along the outline and begin at this drilled hole. 

Locating Studs

Step Three: Time for Drilling 

First, you need to determine whether you’ll be fishing for your cable from the attic or the basement. 

What you need to do now is to drill a hole using the ? inch drill bit in the ceiling right above the switch box location. 

If you are fishing from the basement or crawlspace, you’ll have to drill next to the baseboard instead. 

Now, push a stiff wire or any long tool you can use into the hole you just drilled. This will act as your guide later. 

While you’re at it, go to the outlet you’ll be jumping your new switch out of and remove the plate. Then, repeat the same steps. 

You also need to drill two holes in the top or bottom plate. 

If you’re fishing from the ceiling, then you’ll be looking for a 2×4 beam adjacent to your guidewire, which is the top plate. 

Meanwhile, in the crawlspace or basement, it’s the wall’s bottom, and it’s called the bottom plate.

You need to drill a hole using the spade bit in the top or bottom plate above or below the switch location.

Use your guidewire to know where you’ll be drilling. 

Do the same thing in the area where the outlet is. Your 12/2 Romex wire will be passing through those holes to get to the switch and the outlet. 

But what about cross braces and fire blocks?

In this case, You need to cut an opening for yourself in the drywall to get to the fire block. Then, drill through the fire block or the cross brace. 

Step Four: Fish Your Cable 

For those working from the ceiling, you need to insert your fish tape from the switch opening up to the drilled hole in the top plate. 

Try to maneuver the fish tape with your hands to stay up straight, and try to make it lean a bit on one of the studs if possible. 

This prevents the fish tape from falling over or getting twisted behind the wall. It’s definitely a problem you don’t want to deal with. 

For those working from the basement, you’ll be doing the same thing, but upside down. 

A good tip here is to use the end of a coat hanger to pull the tape’s end out of the hole. 

Now, you need to secure one end of your Romex cable to the fish tape hook using electrical tape. 

Make sure that everything is neat and slim to be able to run through the drilled hole. 

At your switch opening, start pulling the fish tape to pull the cable through the opening. 

Before you’re done here, bring your electrical box for the switch and knock one of the back corners with your screwdriver. 

Pull the cable through this corner and secure the electrical box to the wall.

Now, you need to do the same thing, but with the other end of the cable to fish through the outlet opening. 

Make sure your Romex is long enough for this process. It’s better to be much longer than much shorter. 

After you’re done, pull the cable through the outlet box and secure the box to the wall.

Don’t forget to ensure that the other wires that were already running through the outlet are also secured in the box. 

Also, there should be a cable running from your light fixture to your new switch. 

Step Five: Wire the Light Switch to the Outlet 

Here’s how to wire a light switch and outlet:

  1. In the outlet box, take a utility knife and run it down the 12/2 wire lightly and cut away the protective casing. 
  2. Twist all the ground wires three times together. 
  3. Then, take your pliers, pinch on the grounds, and twist them even more. 
  4. Cut one of the long grounds off to the length of the pre-cut ground wire.
  5. Take a green ground connector and slide your grounds through it, and twist the connector on them tightly. 
  6. Now, it’s time to pigtail our whites and blacks. 
  7. Bring all of your white wires together and strip about ½ inch from the ends of the wires using your wire stripper. 
  8. Take a white wire from an excess piece of 12/2 wire and strip ½ inch from both of its ends. 
  9. Bend one of the ends and twist it with the stripped ends of the white wires tightly using pliers. 
  10. Secure the twisted wire ends with a wire nut and make sure it’s twisted tightly on them. 
  11. Now, repeat the same steps with the black wires. 
  12. Create a tight hook at the ends of the pigtails and the ground wire with your pliers. 

For wiring the switch, you need to follow the same steps without creating a pigtail for your white wires. You only need to secure them with a wire nut and push them back into the outlet. 

Now, you only need to add the final touches.

It’s time to apply your wires to the screws on your outlet, switch, and light fixture. 

For the outlet, hook your ground wire on the green screw so that the hook is bent clockwise. Do the same for the black and white wires. 

However, the black goes on the brass screw and the white on the silver screw. Then, tighten up your screws with a screwdriver. 

Lastly, tighten the outlet to the electric box with a drill. Don’t forget to add your wall plate. 

You’re going to do the same thing for the light switch. This time, you only need to apply the black and ground wires to their screws. 

And now, you’re done. You should celebrate!

How to Add a Switch to an Outlet to Control It?

how to add a switch

In this case, it’s called a switch receptacle. It’s a receptacle that has both an outlet and a switch in it. 

A receptacle is a great way to add a switch to control the outlet without cutting an opening and having to fish for wires. 

You’ll already have a cable running from the breaker panel to the outlet and also another one from the light fixture or any device. 

However, the wiring here is a bit different from wiring a normal outlet or switch. 

You need to determine whether you’ll apply the hot wire to the screw of the switch or outlet. Here’s a video that can help you a lot with this process. 

FAQs

We included a couple of frequently asked questions that can be a great help to you:

What’s the Difference Between “New Work” and “Old Work” Electrical Boxes?

New work electrical boxes are installed on the wall studs directly before adding drywall. At the same time, old work electrical boxes can be used for switches, outlets, etc., that are installed on a finished wall. 

Is There a Specific Height for My Light Switch?

It’s recommended to place your light switches about 48 inches above the ground. This way, you can comfortably reach it whether you’re standing up or sitting down.  

However, it’s best to check your local building codes as this can change from one area to another. 

In Summary

Here you have it, a detailed guide on how to wire a switch off an outlet.

We covered in detail the process of wiring a switch to an existing outlet. Also, we explained how you can add a switch to an outlet to control it. 

Good luck!

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