Abstract: A power switch for use with a personal locator beacon (PLB), or an emergency position indicating radio beacon (EPIRB), that prevents accidental activation of the beacon to prevent false alarm transmission of emergency signals. The personal locator beacon includes electronic circuitry housed in a portable hand-held housing that includes a fail safe power switch which has a lever arm that is selectively movable between first and second offset recessed cavities formed in the housing. The lever arm is rotatable about a shaft between an "off" position wherein the lever arm is received within the first cavity, and an "on" position wherein said lever arm is received within the second cavity. An edge portion formed by the offset cavities stops the lever arm from rotating from the first position to the second position unless the lever arm is manually moved laterally along the shaft to clear the edge portion.