How to Replace a Light Switch?

⚠️ Safety first

• Turn off the power at the breaker — not just the switch — for that circuit.
• Test that the power is off with a non-contact voltage tester before touching any wires. Never assume.

What you need

• A new single-pole switch
• A screwdriver
• A non-contact voltage tester
• Needle-nose pliers (optional)

Step-by-step

1. Cut the power at the breaker box and verify it's off with a voltage tester at the switch.
2. Remove the cover plate and unscrew the switch from the electrical box.
3. Pull the switch out gently and take a photo of the wiring before disconnecting anything, so you can copy it exactly.
4. Note the wires. A basic single-pole switch has two "hot" wires (often black) plus a ground wire (green or bare copper). The two hot wires are interchangeable on a single-pole switch.
5. Disconnect the old switch. Loosen the terminal screws (or release the push-in connectors) and remove the wires.
6. Connect the new switch the same way. Attach the hot wires to the two brass screws and the ground wire to the green screw. Wrap wires clockwise around screws and tighten firmly.
7. Tuck the wires back, screw the switch into the box, and reattach the cover plate.
8. Restore power at the breaker and test the switch.

Notes: A 3-way switch (one that controls a light from two locations) has an extra "traveler" wire and is wired differently — pay close attention to which terminal each wire came from. If you see unusual wiring or aren't confident, call an electrician.

Two similar answers: How to Replace a Toilet Seat? and How to Reset a Honeywell Thermostat?.

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