How to Replace a Light Switch
No need to call an electrician – this is a simple and easy DIY project!
Our living room desperately needed a new light switch. The old one was a super finicky dimmer that was way too sensitive. All we really wanted was a simple light switch to turn the lights on and off. Fortunately, replacing a light switch is pretty easy and straightforward! All you’ll need are a few basic tools, 30 minutes, and about $5-10 for the new switch.
So if you’re in this same situation, here’s a step-by-step guide on how to replace a light switch!
Materials and Tools
I purchased a basic Leviton on/off light switch, which costs about $8. Note that this model also comes in light almond if you need something with more of a cream color.
I also purchased a matching Leviton wall plate, which costs about $2. But you can use the existing wall plate too.
Just about the only real tool you’ll need for this project is a good screwdriver!
We’ll be cutting power to the room that has the light switch, so it’s a great idea to have a flashlight around. This way you can more easily and clearly see what the electrical wiring looks like behind the light switch when the lights go off!
I’m a big fan of Makita tools ever since building a playground for my children, so I had a couple of Makita flashlights around. But even a simple flashlight will come in handy.
While this is optional, it’s really nice to know that no current is running through wires. I personally think some sort of voltmeter/multimeter is an absolute necessity when working with electricity.
Step 1: Using the existing light switch, turn the lights on
In the next step we will turn off power to the light switch at the main electrical panel. To ensure that power has actually been cut to the light switch, it’s helpful to first turn the lights on using the light switch that you will be replacing. That way, when you cut power to the light switch by flipping one of the circuit breakers, you’ll see the lights go off and can be confident that there is no power running to the light switch anymore.
So, head to the light switch that you intend to replace. Here is a picture of the dimmer that I couldn’t wait to replace:
And use it to turn the lights on:
Step 2: Go to the electrical panel and flip the circuit breaker that controls power to the light switch
For safety, you need to cut power to the light switch before replacing it. This can be done at the main electrical panel. Simply flip the circuit breaker that controls the light switch to “off”.
Fortunately, a previous project necessitated the very laborious job of identifying and labeling which circuit breakers control the different parts of our house. If your electrical panel isn’t labeled, it’s just a matter of trial-and-error. Flip a circuit breaker off and see if the lights that were on in Step 1 turned off. If not, flip that breaker back on and flip a different one off. Wash, rinse, and repeat until you find the right breaker.
When you return to the light switch, make sure that the lights are turned off:
Step 3: Remove the wall plate
The wall plate around a light switch hides the hole in the wall that houses the switch and electrical wiring. Remove the wall plate (labeled in blue) by unscrewing the two screws at the top and bottom of the wall plate:
Note that you might need to use a utility knife or screwdriver to pry the wall plate off the wall if it is stuck.
The light switch should now look something like this:
Step 4: Unscrew and pull out the light switch from the wall
There are two more screws at the top and bottom of the light switch that secure it to the wall. Remove these screws so that you can pull out and expose the electrical wiring:
With these screws removed, gently pull out the light switch and attached wires:
With the wiring exposed, you can also use your voltmeter/multimeter to make sure that no electricity is running through the wires.
A Note on Electrical Wiring Colors:
Electrical wiring is color-coded, and if you’ve ever done any electrical work (at least in the U.S.) then you’re probably familiar with the following color-coded convention:
- Black: the black wire is the “live” or “hot” wire
- White: the white wire is the neutral wire
- Bare: the bare (uncolored) wire is the ground wire
- This wire can sometimes be green too
Wiring for a light switch uses this color convention, but appears slightly different due to the nature of what a switch does. In a light switch, current flows in and out of the switch. Current flows in from a power source and current flows out to the lights, outlet, or whatever the switch is controlling. So, a light switch has two “live” or “hot” wires – typically two black wires – as opposed to one “live” (black) and one neutral (white). The switch simply acts as a toggle to either allow or break current from flowing.
Since there are two “live” or “hot” wires, you’ll usually see two black wires attached to a light switch. In my situation, there is one black wire and one red wire. They are both “live”/”hot” wires; the red wire is known as a traveler for multiway switching.
I mention this background information mostly so you don’t get concerned if you see something other than two black wires, or a wire that is an unfamiliar color (such as a blue wire, which – like red – can also link traveler terminals of switches). Just be sure to keep track of which wire goes where. And if you’re ever in doubt, call in a professional electrician!
Step 5: Disconnect the old light switch from the electrical wiring and wire the new switch
Disconnect the old light switch by loosening/unwrapping the electrical wires or unscrewing the screws that connect to the electrical wires.
To attach the new light switch to the electrical wiring, simply secure the electrical wires to the new switch:
On this new light switch, notice how there is a green screw: this is for the (green) ground wire.
There are two methods of securing electrical wires to a light switch. The first is to wrap the electrical wiring around the screws of the light switch, then screw in the screws so the wiring doesn’t move. This is my preferred method, and what I did to install this new light switch (shown in the above picture).
The other way is to push in the wiring into holes on the back of the light switch, then screw in the screws so that the wire gets fastened by a plate:
I suppose this second method is meant to be simpler. However, you’ll still have to wrap the ground wire around the green screw. And I also personally feel that wrapping electrical wires around the screws directly (as opposed to using the push-holes) makes the wiring more secure.
Step 6: Screw in the new light switch
Gently push all of the electrical wiring back into the hole in the wall, then screw in the new light switch to the wall using two screws:
Note that there is a “top” direction/orientation to the light switch, which is indicated by the word “top”. So be sure to properly orient the light switch before screwing it into the wall!
Step 7: Screw in the (new) wall plate
I purchased a new wall plate that matched the color of the new light switch. But whether you have a new wall plate or use the old one, simply screw in the two screws at the top and bottom of the wall plate:
Note that you want to have the light switch in the “on” position since the lights were on before we cut power to the light switch by flipping the circuit breaker!
Step 8: Go back to the electrical panel and flip the circuit breaker that controls power to the light switch
Time to turn power back on to the light switch! Return to the main electrical panel and flip the circuit breaker that controls the light switch to “on”:
When you return to the room with the new light switch, the lights should now be on.
Test the new light switch a few times by turning it on and off to make sure that the lights similarly go on and off as expected.
Congratulations, and enjoy your new light switch!
Did this guide help you to replace your light switch? Let me know in the comments below!
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