Install a Ceiling Light and Switch

Use the force

Here are some electrical do's and don'ts:

• Do test your circuit tester, an essential tool that detects electricity when connected between hot and ground, in a working outlet. Don't trust—verify that the tester will protect you from live electricity.

• Don't use undersize wire or fixtures (lights or outlets). Most lights are wired with 14-gauge wire (connected to 15-amp fuses or circuit breakers). 12-gauge wires should be protected by 20-amp fuses or breakers. Read the breaker or fuse, and choose your wire accordingly. If you can't tell the difference, it's usually safe to use 12-gauge wire.

• Do shut off circuits before you work on them. Then test that the circuit is cold using a circuit tester.

• Don't fool around with aluminum wire, used in some houses built in the 1960s and 1970s. Aluminum is silvery-gray, whereas the more common and much safer copper is dull brown. Connecting to aluminum is tricky; it's smart to hire a qualified electrician to work on aluminum.

• Do make all connections inside boxes. Leave all boxes accessible and do not hide an electrical box behind a wall.

• Don't fool with electrical boxes containing a dense snarl of wires. These boxes, often found in a basement or near the circuit-breaker panel, may be powered by two separate circuits, and it's hard to be sure the power is off. Call an electrician.

• Don't get in over your head. Any time you are thoroughly confused, it's time to call in a professional electrician.

Step 1: Locate the Force

First find a source of power for the new light. An existing outlet is the most common source, but a switch is another possibility, if both the black and white wires are in the box. Also check for an electrical box—a metal or plastic box holding electrical connections—on the basement ceiling.

Once you have located the source box, follow these steps:

1. Shut off the circuit you think feeds the box. Test between each pair of holes in the outlet. If the tester is working, and it never lights, the circuit is cold, and safe to work on.

2. Remove the two mounting screws and pull out the old outlet.

On old wiring, it can be hard to distinguish the black wire. Here's how to tell:

1. Disconnect the wires from the outlet and keep them separate from each other.

2. Turn the circuit back on. Plug a grounded extension cord in a grounded outlet. Make sure your circuit tester lights when you touch the round hole and the small slot in the extension cord.

3. Bring the cord to the supply box. Hold one end of the tester in the round hole and touch the wires with the other end until you find the hot wire. Remember its location.

4. Switch off the circuit breaker or fuse. Now mark the hot wire, which will supply both the old outlet and the new light. Also mark other black wires that are connected in this box.