Abstract: A auxiliary power (AP) input switch includes at least a line power-in terminal, a switched power out terminal, an AC power entry receptacle and a switch actuating element that is switched to an on state to make a connection between the line power-in terminal and the switched power-out terminal, and is switched to an off state to break the connection between line power-in terminal and the switched power-out terminal and to make a connection between the AC power entry receptacle and to the switched power-out terminal. The auxiliary power (AP) input switch that is used as or to replace an emergency cut-off switch for an electrically-driven system, such as a heating system, air conditioning system, refrigeration system, etc., without limitation.