If you're in the market for a light switch, be aware that several types are available. Some dual-pole switches, which control one light from two or more switches, have three or four terminal screws and a ground terminal. Single-pole switches, which control one light from one location, have two terminal screws and a ground terminal. If you're replacing a dual-pole switch, make note of the existing wiring, and if you're at all unsure of how to proceed, hire a licensed electrician to perform the job.

Here's how install a switch yourself:

Materials and Tools:

screwdriver
circuit tester
needle-nose pliers
wire strippers
light

Steps:

Remove the old switch

1. Shut off the power at the circuit-breaker box.

2. Remove the cover plate and test the terminals with the circuit tester. If the tester doesn't light up, there's no power going to the switch.

3. Remove the screws that hold the switch in place, and pull the switch from the wall.

4. Loosen the screws holding the wires to the switch, remove the wires, and remove the switch. In newer switches, the wires may go directly into the switch, where they are held in place by clamps inside the switch. These switches usually have a slot into which you can insert a small screwdriver to loosen the clamps.

Install the new switch

1. Begin by bending the end of the ground wire into a small hook, placing the hook over the ground terminal of the switch and tightening it in place.

2. Attach the remaining wires to the terminals and tighten them in the same way. Your new switch may have holes that allow you to insert the wires without using the terminal screws. If so, straighten the wires, press them into the holes as far as they'll go and then tug on them to make sure they're held securely in place.

3. Gently press the switch back into position and secure it in place with screws. Replace the switch cover and turn on the power at the circuit-breaker box.