An argument could be made that light switches are among the most important energy-saving tools in our homes because they allow us to easily turn off lights when lighting isn’t needed.

Here we look at how to install or replace light switches. Why might you want to do this? For starters, light switches wear out because of their frequent use.

When they wear out, they don’t work or, worse, they give off sparks. A light switch that gives off sparks is a fire and shock hazard and should be replaced immediately. (Because common light switches are relatively inexpensive (typically less than $10), it doesn’t pay to try to fix a broken one. Instead, you just replace it.)

Another reason for replacing a light switch is better functionality. As discussed in the Light Switches Buying Guide, light switches have come a long way in recent years.

Today, options include dimmers, motion-sensing switches, timers, central lighting controls—and more. Any one of these options may perform much better at a given location than a conventional (“single-pole”) light switch.  (You can’t, however, replace a single-pole switch with another type that requires more wires, such as a three-way switch.)


Appearance is yet another reason for switching switches. Quite simply, new light switches can add a contemporary look to a room.

Caution: Before working on a light switch, shut off the power to the circuit—never work on an energized circuit. For information on how to do this. See How to Turn Off a Circuit.


How to Replace a Single-Pole Light Switch

If a switch doesn’t work, first make sure the problem is with the switch and not the light or device it’s supposed to power. Put a new bulb into the light fixture or plug a working lamp or other appliance into the switch-controlled receptacle to make sure the switch is faulty.

When you replace a switch, make sure you check the amp and voltage ratings on the back of the old switch. The new light switch should have the same ratings. If you have aluminum wiring (the metal part of the wires looks silvery), be sure to get a replacement switch marked “CO/ALR.” Unmarked or CU/AL switches should be replaced with CO/ALR switches.

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About Don Vandervort
Don Vandervort has developed his expertise for more than 30 years as a remodeler and builder, Building Editor for Sunset Books, Senior Editor at Home Magazine, author of more than 30 home improvement books, and writer of countless magazine articles. He appeared for 3 seasons on HGTV’s “The Fix,” and served as MSN’s home expert for several years. Don founded HomeTips in 1996. Read more about Don Vandervort