Lowe's, The Home Depot, Wal-Mart and Amazon.com are some stores that offer outdoor lighting photocells. Photocells stocked by these suppliers include fixed and swivel models, as well as those that detect daylight, incandescent light and motion.
Fixed daylight-detecting photocells are typically used for exterior lighting to turn the outside lights on at dusk and off at dawn, reducing electrical use and providing security. Incandescent light detectors perform similar functions indoors.
Motion-detecting photocells are typically used for enhanced security options, such as turning on additional outdoor flood lights when sensing a presence or triggering a security system if an intruder is detected.