John,

The light fixture is actually a medicine cabinet with a 20 watt
flourescent bulb fixture on each side. Short of taking off the plates
under each bulb fixture, I'm not sure of a way of diagnosing the wiring
to and from this unit. This cabinet unit also has its' own single
outlet and a light switch. I suppose I could just leave the main light
switch on and control the lights by the cabinets' own switch, but the
cabinet switch is on the far side of the cabinet with respect to the
door entry of the bathroom. Plus, I'd also have to either bypass the
main light switch or inelegantly tape it 'on' to prevent visitors from
shutting off the switch, killing the power to the stereo memory.