A LED as light sensor
SE Wireless Motion Sensor Light – 10 Super-Bright LED
$7.14
nstantly add motion-activated light for security and safety – indoors or out*Infrared technology senses both movement and heat for fewer false activations; daylight-off function*Compact (3″ x 3″) and lightweight (4.3 oz) lets you install almost anywhere; easy-mounting slot *10 super-bright LED [...]