For best effectiveness, position a motion sensor light to cover the walks leading to your front and back doors and the driveway (see lead illustration). That way the lights will come on when you come home at night. You can also use them to light up decks, patios and any potentially hazardous locations such as around stairways and swimming pools.
If improved security is a priority, position the motion sensored lights to cover all the approaches to your house, including fence gates, the patio door, the darker areas of your yard, and around trees and bushes. Good lighting can’t guarantee security, of course, but it’s one of the best low-cost ways to get unwanted intruders to back away.
Ideally, it’s best to mount motion sensing lights 6 to 10 ft. above the ground and position it so that most movement will occur across the sensitivity zone rather than directly toward the detector. Obviously you can’t always do that if you use existing light locations. One solution is to buy a remote motion sensor unit that you can mount some distance away from the light itself . The wires connecting them to the light are low-voltage and not dangerous, so you don’t have to enclose them in metal or plastic conduit.