[Jack21]

Your "dome light" is drawing juice through a resistance somewhere. Better find it and explain it, or disconnect it.

Dome lights usually work as a complete-the-ground circuit. The hot wire runs through the bulb(s), then to a grounding switch on the door. A voltage at the switch would read the resistance of the dome light bulb.

So, if you have a dome light wire, and no dome or courtesy light, you have???