Abstract: An improved fluorescent light adapter for incandescent light fixtures. The adapter may be directly wired in to the Edison light fixture, and also includes locking structure to prevent theft. Specifically, the adapter includes a lower housing with a plurality of channels, some of which include locking ramps for mating with inwardly directed teeth on the lower sleeve portion of a standard Edison light fixture. To retrofit an existing light, the standard Edison socket is disassembled and the adapter is simply pressed downward locking onto the lower sleeve. The adapter may be provided with an on/off switch or a three-way switch, and includes a variable height neck portion for adapting to a variety of lamp shades and harps.