Ask The Fix-It Club syndicated weekly newspaper column

Fixing a Light Switch

Q: Every time I turn on the light in my bedroom, I hear a crackling sound at the switch. I'm afraid it's a fire hazard. Do I need to call an electrician?

A: You're right that a crackling light switch is a potential fire hazard. But you don't necessarily need an electrician. Electrical switches are so simple in design and so inexpensive that just about anyone can replace them safely. Let's see how the Fix-It Club tests and replaces electrical switches.

An electrical switch breaks the flow of electric current. When turned on, a switch completes the electrical circuit and current flows to the light or other device the switch controls. When the switch is off, the electrical circuit is not complete, denying power to whatever the switch controls.

Most electrical switches wear out from use in 5 to 20 years, depending on quality and frequency of use. Additionally, wires can become loose and not make connection. You can find replacement electrical switches at most hardware stores and home improvement centers.

Fix-It Tip

If you're buying a new switch that will get lots of use, spend a little more and buy one that is labeled "commercial" or "spec-rated." Internal parts are sturdier and will stand up to use longer.

To test an electrical switch:

1. Turn off power to the switch's circuit at the electrical service panel, often located in the garage. Identify the correct circuit breaker and turn it off, or find the appropriate fuse and unscrew it from the panel. You may need a helper so that one person breaks a circuit or unscrews a fuse and the other determines what it controls inside the house.

2. Remove the switch cover plate and use a continuity tester (see www.FixItClub.com: Using a Continuity Tester) to make sure power is off before proceeding.

3. Disconnect the old switch by removing the top and bottom screws that hold the switch to the electrical box mounted in the wall.

4. Pull the switch toward you to expose the wires on the side and rear. If a wire is loose or broken, you've found a possible cause of the crackling.

Once the power is off, remove the switch from the electrical box.

5. Unscrew the terminal screws on the switch about 1/4 inch and remove the wires. Some switches, instead, have wires inserted into holes in the rear of the switch; if this is the case, insert a small thin screwdriver in the slot below the wire to release it.

6. Use a continuity tester to test the switch. Clip one probe to each of the two terminals, then flip the switch on and off. The tester should light only when the switch is on. You also can use a multimeter (see www.FixItClub.com: Testing with a Multimeter) set to resistance in ohms for this test. If the switch is faulty, replace it.

To replace an electrical switch:

1. If any wires from the box are damaged, remove the damaged portion, making sure you have sufficient wire left to reach the terminal box.

2. If necessary, use a wire stripper to remove insulation from the last 3/4 inch of the end of the wires.

3. Use the strippers or pliers to bend the end of the wire in a semicircle so it can wrap around the terminal screw. If there are no terminal screws on the switch, insert the straight wires into the appropriate holes on the back of the switch.

4. Attach the wires to the terminals and tighten them.

5. Replace and screw the switch into the terminal box, making sure the switch is plumb -- straight up and down.

6. Replace the cover plate, restore power, and try the switch.

For additional information on fixing household things that break, visit www.FixItClub.com.