Abstract: A power adapter for timed control of auxiliary electrical loads is provided for connection between a streetlight fixture or the like and a control module of the fixture. The adapter has a weather-resistant housing and an electrical jumper in the housing extending a power source connection to an input of the module, another jumper returning a control output from the module to a main load of the fixture. An auxiliary socket at the side of the housing powers the auxiliary load, which can be a holiday lighting display. In one version, the adapter has a clock timer for controlling the auxiliary load independently of the main load. In another version, a programmable delay timer, synchronized with commencement of main load operation, terminates operation of the auxiliary load following a predetermined interval of main load operation.