Originally Posted by wahoonc
Do you have a scare light? It looks like a backup light from a semi truck. Big round and clear/white lens on it. Mine is mounted on the right side up near the front. I have seen them on 67 models too.
On a '68, the scare light is
the porch light Jim refered to in the initial post.
Doug supplied the correct answer, the switch controls the ceiling light. Although you can still control the ceiling light with the knob while the power is on, the switch by the door lets you turn on the light before you get inside instead going completely inside a dark trailer.
It's a nice feature in a dark area
, if you can find one of those anymore
It's also worth noting that if that switch is in the off position, there is no power to the ceiling fixture. If you don't know about the switch, you spend a lot of futile time trying to get power to that light fixture.