Abstract: A switch with a cantilevered leaf spring as the movable bi-metal contact lever can be switched "ON" or "OFF" by a rocker pivoted in the housing. No lost motion plunger is required and no centor terminal is provided in the housing bottom wall. The contact lever also has a temperature sensitive shape so it will bend upwardly toward the rocker to open the switch contacts in response to an overcurrent condition. The rocker is returned to "OFF" by such a shape change in the bi-metal contact lever.