What is the definition of a motion sensing light switch? A motion sensing light switch is a device that is used to control the lights in a room by detecting movement within a certain range. The switch is typically installed in a room or hallway and is able to sense when someone enters the area by detecting infrared radiation given off by a person’s body. Once the motion is detected, the switch will turn on the lights automatically, allowing for a more energy-efficient environment. The motion sensing light switch has become increasingly popular in recent years due to the energy savings and convenience it provides. The switch is designed to save energy by only turning the lights on when it is needed, and by turning them off when no one is present. Additionally, the switch is easy to install and provides a great convenience to users as they do not have to manually switch the lights on or off. Overall, a motion sensing light switch is a great way to save energy and make life a bit more convenient.