Abstract: In an electric switch of the kind comprising a rectilinearly movable contact carrier (31), contacts (33) of which cooperate with fixed contacts (10A-17A,20A-25A) of a housing (19) defining spaces containing the fixed and moving contacts, which spaces are vented to atmosphere, the moving contact carrier (31) is provided with barriers or partitions (40) that cooperate with corresponding barriers or partitions (41,42) of the switch housing to subdivide the contact containing spaces in a labyrinthine manner. As the moving contact carrier (31) moves from the closed to open contact position, the respective barriers or partitions (40-42) of the contact carrier and the housing move relatively in a direction towards one another. This serves to minimize the risk of ionized gases passing between contact containing spaces of the housing (19) upon opening of the switch contacts.