In electrical engineering, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another. The mechanism of a switch may be operated directly by a human operator to control a circuit (for example, a light switch or a keyboard button), may be operated by a moving object such as a door-operated switch, or may be operated by some sensing element for pressure, temperature or flow. A relay is a switch that is operated by electricity. Switches are made to handle a wide range of voltages and currents; very large switches may be used to isolate high-voltage circuits in electrical substations.

Switch is an American action-adventure detective series starring Eddie Albert and Robert Wagner. It was broadcast on the CBS network for three seasons between September 9, 1975 and August 20, 1978, bumping the Hawaii Five-O detective series to Friday nights.

A switch is an electrical component which can break an electrical circuit, interrupting the current or diverting it from one conductor to another.