If it does not leak anything when it rains, It sounds like either the drain holes in the condensate pan are blocked or the coils are dirty. When the pan drain holes get clogged the condenser fan can blow water into the camper. I would start by removing the inside assembly, pull the knobs off and it should have 4 or 6 screws. Then run the AC for awhile and see if you can tell where its coming from. Next you may need to pull the exterior shroud off and take a look.
What brand is it? Some older Carriers did not have drain holes in the pan but a slinger on the fan would blow the water through the coil and out onto the roof. If the coil needed cleaned it would create a problem.