Abstract: The control circuit is preferably provided in an integral unit with a momentary on-off switch, preferably inside a switch housing box and adapted to replace a common wall switch to provide for the automatic turn-off of the light or other load operated by the switch after a presetable period of time. The circuit is constructed so as not to require a third wire (usually a power lead) at the unit. The use of low power logic circuit controls, employing preferably CMOS chips enables use of a capacitor storage element of manageable size, with very low power consumption of the circuit in its "off" state. The "on" duration of the light is adjustable over a suitable time range and the circuit is further characterized by a "flashing" period preceding total turn-off.