Home Improvement and DIY
Know the switch, check the circuit, and stop if the wiring is unclear.
A switch that clicks but no longer controls the light may need replacing, or it may point to a wiring problem. Identify the circuit and verify power is off before touching wires.
A single-pole switch controls a light from one location; a 3-way switch controls it from two. Match the type before buying, since each has a different terminal layout.
Switch off the correct breaker; the wall switch alone is not enough. Test the box with a properly rated tester, checking it on a known live source before and after.
Line brings power in, load carries switched power to the light, and travelers connect 3-way switches. Ground provides an equipment safety path; neutral usually stays out of a basic switch.
Use a matching single-pole switch. Transfer the incoming and switched conductors to the corresponding terminals, connect ground, and leave any neutral splice intact.
On a 3-way switch, put the common conductor on the terminal marked common, often the dark screw. Travelers go on the other two terminals; identify wires by their old connections.
Secure the switch and cover plate before restoring breaker power. Test the light from every location; a 3-way setup should work from either switch regardless of the other's position.
If the breaker trips, the switch sparks, or you notice a burning smell or heat, turn power off and leave it off. Never keep resetting a tripped breaker or work energized.
Replacement costs depend on switch type, local labor rates, access, and wiring condition. Ask an electrician for a quote that separates the device, labor, and any diagnosis or repair.
Three wires can describe different arrangements. Identify the switch function and each conductor; never choose a replacement or terminal by wire count or insulation color alone.
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