How to Wire a Light Switch in 5 Easy Steps
Installing or replacing a light switch is a relatively easy do-it-yourself project that most homeowners can tackle. With some basic tools and following these steps, you can wire a light switch safely in your home.
Things You'll Need
Before getting started, make sure you have the following materials:
- Wire strippers - to strip the insulation off the wires
- Needle-nose pliers - to twist wires together and bend hook shapes
- Voltage tester - to make sure the power is off before working
- Phillips screwdriver - to remove switch plate and disconnect wires
- Replacement light switch - match amperage and voltage of old switch
- Electrical tape - to cover wire connections
- Wire nuts - to join copper wires together
Step 1: Turn Off Power at the Circuit Breaker
The first and most important step is to turn off the power to the light switch at the circuit breaker box. Make sure to test that the power is off using a voltage tester before working on the switch wiring. Working on a live circuit can result in a serious shock.
To turn off the correct circuit:
- Locate the circuit breaker box in your home, usually in the basement, utility room, or garage.
- Open the metal door and locate the switch labeled for the room with the light switch.
- Flip the breaker switch to the "Off" position so it is no longer raised.
Step 2: Remove the Existing Light Switch
With the power to the switch turned off, you can now safely remove the existing switch:
- Unscrew and remove the switch plate covering the switch assembly.
- Unscrew the screw terminals securing the wires to the switch. There may be two or more wires connected to the switch.
- Carefully pull the switch away from the switch box, keeping track of which wires are connected to which terminal screw.
Step 3: Connect New Switch Wires
Refer to the wiring diagram on the new replacement switch to connect the wires correctly:
- The black hot wire from the power source gets connected to one screw terminal.
- The black wire leading to the light fixture gets connected to the other screw terminal.
- The bare copper or green ground wire gets connected to the green screw terminal on the switch.
- Twist the bare wire ends together clockwise using needle-nose pliers.
- Secure each twisted wire end under the corresponding screw terminal and tighten down.
- Make sure no bare wire is exposed once connected to the switch.
Step 4: Mount the New Switch in the Box
You're almost done! Now mount the wired switch back into the switch box:
- Carefully tuck wires back into the switch box, coiling them loosely.
- Position the switch properly oriented in the box and attach with the screw.
- Install the plastic switch plate cover and screw it back in place.
Step 5: Turn Power Back On
The last step is to turn the circuit breaker switch back on to restore power:
- Return to the circuit breaker box and locate the correct switch.
- Flip the switch to the "On" position. Listen for a click.
- Test that power is back on by flipping the light switch on and off.
It's always a good idea to test a newly wired light switch several times to ensure proper connection. If the light doesn't turn on or flickers, double check that all wire connections are tight and no copper is exposed. With the simple steps above, you can install a light switch quickly and safely.