In electrical wiring, a light switch is a switch most commonly used to operate electric lights, permanently connected equipment, or electrical outlets. Portable lamps such as table lamps may have a light switch mounted on the socket, base, or in-line with the cord. Manually operated on/off switches may be substituted by dimmer switches that allow controlling the brightness of lamps as well as turning them on or off, time-controlled switches, occupancy-sensing switches, and remotely controlled switches and dimmers. Light switches are also found in flashlights, vehicles, and other devices.
Two decorator-style rocker switches and wiring, as installed in the United States. Shown here will be fastened to this recessed, non-metallic box, then a cover plate is installed. This "double gang" (two unit) installation uses non-metallic-sheathed cable and twist-on wire connectors.
Two light switches in one box. The switch on the right is a dimmer switch. The switch box is covered by a decorative plate.
Vintage push-button light switches
Internal components of a toggle switch
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of switch is an electromechanical device consisting of one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching current can pass between them, while when the contacts are separated no current can flow.
Electrical switches. Top, left to right: circuit breaker, mercury switch, wafer switch, DIP switch, surface mount switch, reed switch. Bottom, left to right: wall switch (U.S. style), miniature toggle switch, in‑line switch, push-button switch, rocker switch, microswitch.
Three push button switches (Tactile Switches). Major scale is inches.
A toggle switch in the "on" position
Triple-pole single-throw (TPST or 3PST) knife switch used to short the windings of a three‑phase wind turbine for braking purposes. Here the switch is shown in the open position.
