Meaning

noun control consisting of a mechanical or electrical or electronic device for making or breaking or changing the connections in a circuit

noun an event in which one thing is substituted for another

noun hairpiece consisting of a tress of false hair; used by women to give shape to a coiffure

originPerhaps from Middle Dutch swijch (“twig”), first attested in c. 1592. The mechanical device for altering the direction of something sense is first attested in c. 1797, pertaining to pivoted rails on minecart railways, which were once wooden.

Etymology from Wiktionary, CC BY-SA 3.0