How to Replace a Light Switch

But can you change a light switch yourself? Or do you need an electrician? The answer depends on your skills or willingness to do the work. You don’t legally need to call an electrician to change or replace light switches unless it’s a new home build, so if you’re motivated to DIY replace the light switch, it’s simple enough for most people to learn.

Light switch replacement is generally pretty straightforward. You’ll connect two hot wires from the old switch and reconnect them to the new one.

First, let’s gather the tools you’ll need. Then, we’ll go over the replacement process step by step and discuss everything you’ll need to know to make the job successful.

Now that that’s out of the way, let’s get to work!

• Before you begin, remove the switch plate to confirm your new switch is compatible. It should have the same number of wire contacts and fit the box you’re installing it into.
• Next, go to the electrical panel and switch off the circuit breaker for the switch you’re changing. You may need to unscrew a fuse if it's an older system. It is imperative to ensure the power is off before you replace your switch. You could risk electrocution if the wires are still hot, even if the switch is broken.
• Now, use a voltage tester or go back to the wall and flip the wall switch to confirm that the breaker is off.
• Remove the light switch cover and test the circuit. When you take the switch cover off, you’ll see a box around the switch. Use your circuit tester to see if the current is going through the switch. Place the tip of the probe into the box beside the screw terminals. If it lights up, there is power, meaning you’ll need to return to the breaker panel and be sure you’ve switched off the correct circuit.

Removing the Old Light Switch

Once you’ve determined the switch is off, you’re ready to remove the old switch.

• Remove the mounting screws that hold the switch in the box.
• Pull the switch and attached wires out slightly by the straps (the tabs that you just removed the screws from), taking care not to damage any wiring.
• Document how the wires are attached to the switch. Take a photo on your phone if needed.
• You are only concerned with the wires directly connected to the switch.
• Depending on how old the existing switch is, you might see:
• Two different colored wires. The black wire is the incoming “hot” wire, while the outgoing wire is usually white but could be any color.
• If there are two same-colored wires, the hot wire will be marked with electrical tape.
• Grounding wires are either green or bare copper.
• Older switches might be covered with cloth or rubber insulation and not color-coded.
• Black wires go to brass screws (sometimes black), green/copper ground wires to green/copper screws, and white wires (usually neutral).
• If a wire is marked with electrical tape, it is not neutral, regardless of the color.
• Document (first) and unscrew every wire nut and all switch wiring, keeping track of which wire goes where.

Final Thoughts on Replacing Light Switches

Hopefully, your light switch replacement project went well. If your wiring looks dodgy, you may need to call an electrician to rewire the switch to ensure it’s safe. Some switches might be more complicated, so consult a professional if necessary.

Most household light switches are not hard to replace, but safety always comes first.