frigking rainforest
It is probably the condensation is not draining from the catch pan. To correct the problem:
1) Turn off the a/c unit and open the circuit breaker.
2) Remove the plastic grill work cover on the inside of the RV at the ceiling, so that you can see up inside of the unit.
3) With a good strong light, look up into the area where the cool air exits the uint. You should be able to see the cooling coils, on the side of the air channel. At the bottom of the cooling coil there should be a catch pan, probably made of plastic.
4)Look or feel for a drain hole in the pan. It may be in a corner, or it could be a depression more to the center of the pan. Once you locate it, you probably need to clean it. If the pan is full of water it means the drain is plugged, but even if it isn't, the drain may well be partially plugged so that it does not drain quickly enough to keep up when humidity is high. That is very common.
5) Use a spray can of compressed air or some other means to blow out the drain hole, or clean it with a pipe cleaner or such. Do this carefully as you do not want to make a leak in the pan. The drain may not be accessable to you, so if not see the part following step 7.
6) Once the drain is clear it is also a good idea to wipe out the pan with a mix of bleach and water and to run some of the mix through the drain hole to make sure that there is no mold or fungus growing there.
7)Replace the grill face, turn on the circuit breaker and test the a/c unit.
If you can't access the drain from the inside, which on some units you can not, then you will have to go to the roof and remove the shroud and locate the drain pan from there. It will be under the cooling coils. On my DuoTherm units, I can locate the pan from the inside, but it must be cleaned from the outside, on the roof. But you should be able to see both the cooling coils, the blower and at least the edge of the drain pan. That should help you to locate it from above. The problem is that the condensate is not draining away from the cooling area quickly enough to prevent it building up and blowing drops into the RV. The moisture should drain out on to the RV's roof and then run off.
This is by far the most common cause of this problem.