switch has 21 distinct synonyms spread across 9 of its 14 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
control consisting of a mechanical or electrical or electronic device for making or breaking or changing the connections in a circuit
an event in which one thing is substituted for another
“the replacement of lost blood by a transfusion of donor blood”
hairpiece consisting of a tress of false hair; used by women to give shape to a coiffure
railroad track having two movable rails and necessary connections; used to turn a train from one track to another or to store rolling stock
a flexible implement used as an instrument of punishment
a basketball maneuver; two defensive players shift assignments so that each guards the player usually guarded by the other
the act of changing one thing or position for another
“his switch on abortion cost him the election”
change over, change around, as to a new order or sequence
Synonyms, antonyms and the broader and narrower relations for switch come from Princeton University’s WordNet. Full sources and licences.
lay aside, abandon, or leave for another
“switch to a different brand of beer”
cause to go on or to be engaged or set in operation
“switch on the light”
reverse (a direction, attitude, or course of action)