Originally 'a thin twig or whip,' probably from Dutch — the electrical sense dates from 1797.
A device for making and breaking an electrical connection; also, a slender flexible shoot cut from a tree.
Originally meant 'a thin flexible twig or riding whip,' probably from Low German or Dutch, related to Middle Dutch swijch 'bough.' The electrical sense dates from 1797, from the idea of a lever that flips (switches) between positions. The verb 'to switch' (change, swap) followed from the abrupt motion of switching tracks.