Tail Lamps 1939 Deluxe

[Woodie1]

We have a 1939 Deluxe sedan that I'm struggling with. I can only get 4.8 volts at the tail lamp pins. I check for ground on the pins in the tail lamp sockets & they are grounded on both pins with 1 bulb still in the socket. If both bulbs are out, then only the bottom pins are grounded in both tail lamps. If I unplug the black tail lamp wire that runs from the front of the car, then the pins in the tail lamps are no longer grounded. It looks like I may have to look inside the light switch bulb for the problem. I feel that the tail lamp pins should never be grounded. I've run out of steam for the moment. I'll have to wait until tommorow to check further. I'm sure those grounds ar why the lights aren't as bright as they should be.