Abstract: A self-contained unit that is screwed into a lamp socket, and itself having a socket into which a light bulb is screwed. It includes an internal electronic unit, which functions in response to variation in capacitance, for turning on the bulb, and increasing its brilliance in steps, and turning it off. A sensor bracket includes a finger connected at one end with the electronic unit and extends outwardly from the unit and has a set screw turned in against the lamp socket in which the unit is mounted.