The number one reason stairwells are dangerous? Bad lighting. We resolved that problem with our LED Stairwell Lighting. They're an excellent indoor lighting solution for parking garages, stairways and hallways, or schools. Really, anywhere stairwells exist indoors, so can our LED Stairwell Lighting. The photocell ultrasonic motion sensor is more accurate than microwave sensors and can detect motion up to 15 feet away.