Abstract: A control circuit for controlling the operation of an electrical lighting device, such as a gas discharge ballast or an incandescent lamp, and which can replace a standard switch and requires connection only to the hot wire of an AC power line. The control circuit has a switch encoder which couples two opposite polarity thyristors between the hot wire of an AC power line and the hot wire running through the wall to the fixture. The thyristors are controlled by switches such that the AC waveform is transmitted over the power wires either with the small zero crossing step delays inherent in thyristor switching, or with a chopped waveform such that the transmitted AC waveform has positive going zero crossing step delays or negative going zero crossing step delays. The transmitted AC power waveform is used to power the electrical lighting device as well as to control the operation of the electrical lighting device by connection to a decoder.