Abstract: A key-actuable electrical switch for a key having a distal end portion including a hook and an abutment section, a central portion including key cuts defining a tumbler pin code and a proximal end shank portion. The switch includes a housing having a first portion rotatably receiving a key core including a plurality of tumbler pins, the first portion including a set of tumbler pin retraction bores housing springs for urging the tumbler pins into engagement with the tumbler pin code portion of the key. The key cooperates with the key core, tumbler pins and retraction bores to permit sliding movement of the key longitudinally of the core in the locked position and in at least one other switch actuating position. The switch includes a first pair of circuit terminals and a movable contact carrier having a first position opening a circuit between the first pair of circuit terminals and a second position closing the circuit between the first pair of circuit terminals.