How to Install a Security Light

Things that go bump in the night are scary. Even when the thing doing the bumping is you, because it's pitch black and you can't find your house keys. Then, you'll wish you had a motion-sensing security light. Whenever anything moves within its range, this handy sensor kicks on the light, illuminating your driveway or walk. Of course, it also sheds a little light on those who prefer the dark. Like burglars, teenagers in the family car and the occasional deer about to chow down on your roses.

Do It Yourself or Hire a Pro?
This an easy project, even for a novice, if your home already has an exterior light. You'll save more than half of what an electrician would charge to do the job.

If you don't have an exterior light or don't want to run electricity to a new location, hire a contractor.

Step by Step
1. Removing an existing light. Turn off the power. Unscrew the bolts that secure the old light to its outlet box. Then pull the light assembly gently away from the box. Before handling any of the wires, test for voltage once more with a voltage tester. When you're sure the power's off, unscrew the wire connectors. Remove the light and wipe away any cobwebs or bug nests in the area.

2. Wiring a new light. Position the new light's weather-tight gasket over the outlet box and, using wire connectors, connect the wires in the box to the wires on the new light. Connect the light's black wire to the black wire coming out of the box, and the light's white wire to the white wire coming from the box. If there is an existing green or copper grounding wire, it will likely be attached to the box. Detach it from the box and attach it to the grounding screw on the light.

3. Attach the light to the box. Stuff the wires back carefully and position the light's base plate over the outlet box, then screw in the bolts that hold the light's base plate to the box.

4. Aim and adjust the motion sensor. Motion-sensing security lights adjust in lots of ways, so carefully read the instructions that come with the light. You may be able to adjust the distance at which it detects motion, as well as the amount of motion (called sensitivity) that triggers the light, and the amount of time the light stays on once tripped.

Aim the sensor toward the area where you want the light to "see" movement. Ask a helper to walk through the sensor's field of view. This may take some adjustment over several nights: raccoons kept triggering our lights until we gradually raised its sensitivity setting. The light should come on and stay on for the amount of time you've set. If not, readjust it.

Learned the Hard Way
If you bought a light with plastic components, handle it gently in cold weather; it's brittle then. Also, if you can reach your fixture without using a ladder, it's probably too low. It would be as easy for a burglar, for example, to reach up and simply unscrew the bulbs. If that's the case, mount a new outlet box and light assembly out of reach.

Hire a Pro
Because this is such a small job, you may have a problem finding an electrician willing to do it. Also, many electricians won't do any installation in which the customer bought the materials (yes, you do pay a premium when the electrician buys the materials). This isn't dishonest or merely a way to jack up the price. The fact is, electricians may have an honest and hard-earned preference about what they install. Besides, most will want to look at the job first, then talk to you about what to install. Bear in mind that an electrician must be paid for visiting your house, spending time there and making a trip to the home center or electrical supply house to buy the light. This is in addition to the time it takes to actually install the light. In addition, if there's no light in that location already or if electrical problems exist, your costs will increase substantially.

Design-Wise
Motion-sensing security lights come in a lot of styles, from decorative coach lights with fixed motion-sensing elements to utilitarian floodlights with adjustable motion-sensing elements mounted on an arm. First decide if you want a fixed or adjustable motion-sensing element, then choose a light style that suits your taste.