1. AN ELECTRIC SWITCH FOR USE IN A LINKAGE WHICH COMPRISES FIRST AND SECOND LINK PORTIONS DISPOSED IN SPACED COAXIAL RELATIONSHIP, SAID SWITCH COMPRISING AN ELONGATED TUBULAR HOUSING RIGIDLY CONNECTED AT ITS ONE END TO THE FIRST LINK PORTION AND HAVING THE SECOND LINK PORTION EXTENDING INTO THE OTHER END THEREOF AND MOVABLE AXIALLY WITH RESPECT THERETO TO A LIMITED EXTENT, A HOLLOW ELONGATED PLUNGER RECIPROCABLE IN SAID SWITCH HOUSING AND SECURED TO SAID SECOND LINK PORTION INSIDE SAID HOUSING TO THEREBY POSITIVELY LIMIT THE AXIAL MOVEMENT OF SAID SECOND LINK PORTION IN ONE DIRECTION RELATIVE TO SAID HOUSING AND SAID FIRST LINK PORTION, AN ELONGATED COILED COMPRESSION SPRING DISPOSED IN SAID PLUNGER AND CAGED BETWEEN IT AND ONE END OF SAID HOUSING TO URGE SAID PLUNGER IN THE OPPOSITE DIRECTION WITH SAID SECOND LINK PORTION, AND AN ELECTRIC TERMINAL ON SAID SWITCH HOUSING ENGAGEABLE BY SAID PLUNGER FOR CIRCUIT CLOSING PURPOSES WHILE LIMITING ITS MOVEMENT IN THE LAST MENTIONED DIRECTION UNDER ACTION OF SAID SPRING.