Abstract: An electric switch for a wrist-watch equipped with electric or electronic circuitry requiring a on/off switching at will. An enclosure assembly defines an enclosed chamber wherein an electrically conductive liquid can move responsive to different positions given to the watch. Two electrically conducting parts, structurally isolated from one another, are exposed inside and outside the enclosed chamber. The conductive liquid establishes an electrical connection between these two parts only when it is in a predetermined location within the enclosed chamber, which occurs only when the watch is held in a predetermined vertical or slanting position. The enclosed space is annular and is provided with baffle elements for preventing the liquid from reaching the aforementioned location by simple inertia when the watch is subject to shaking, shocks, or acceleration.Such an electric switch is suitable for controlling the illumination of the display of the watch.