Maybe some more checking is worth the time?
We need to keepin mind that Rv are wired fart different than house wiring and that sometimes can work out to bean advantage. Sometimes not but worth a check, perhaps?
I assume you are saying the light near the vent is operated by a switch at some location?
I would want to check that light to make sure how it is wired as there are times when there is a hot wire there, even though it would not be in house wiring. Far different codes and practices on the two!
Some things I would want to check first:
1. If I take the light off the ceiling, are there ID "codes" stamped on the wiring if I pull several inches out of the ceiling?
If you find the ID, try to use this chart to find what each wire does:
https://www.winnebago.com/Files/File...ical_guide.pdf
You may get lucky and find a wire which is hot and then goes to the switch, so that it might be used there.
OR you may not be so lucky and need to do more.
One thing to consider is how much current that light is fused/ breakered to carry as the newer LED lights may have really small fuses.
But if the wiring to the light is large enough to also support the fan, there may be a method that is not quite as nice but can still work.
What if one needed to use that power but did notwant the light on all the time the fan was on? Can you see adding a small switch at the light itself to turn the light and fan on but turn the light off when you only want the fan? Or there may be times when you would turn both on at the switch but not want the fan running? That would mean a switch at the fan and possibly also at the lights but it can work with just a bit of extra thought and a couple two dollar switches to get it to work your way!
The big advantage is that none of this will jump out at shoppers and none of it is run on the surface as you only need to fish wires a few inches from the fan to the light.
I sharpen a wooden dowel to press through the insulation from point "A" to "B" as there is less danger of the dowel as it tends to not punch into things as bad as wires or a drill bit might! A hole drilled in the dowel can then let you pull something like a thread or thin wire back before tying on the real permanent wiring.
You are in a place where the prime need is to avoid damage! Not a good time for an electric drill as they can find wires to mess up, even when we can't see them!
EDIT:
Secondlook makes me ask what is under the cover just to the right?
Linear Mode
