Switches control power to light fixtures and power outlets or receptacles. A light switch is a switch, most commonly used to operate electric lights. Today, there are many variation and design of light switches, push button, toggle, rocker/decorator, illuminated switch, voltage class, tamper resistance, mercury switches, pull chain/pull cord, dimmer switch, and electronic switches.
The following schematic shows a typical household light switch wiring (toggle switch). This switch design has an arrow-shaped armature that floats between the contact points when the switch is in the off position. The strip of metal (B), making contact with point ‘A’, completing the circuit and thereby conducting electricity to the light.