Dosen't matter the make or brand of your RV. Water in a ceiling light fixture is indicating a leak. Somewhere, there's a leak on your roof, possibly the ac unit. Water may be building in the area between the roof and the ceiling or just running down the wire powering the light.
Check the ac mounts to the roof, and any items poking through the roof to make sure their seals/caulking is not cracked or has a gap.
Steve & Cheryl + Charlie & Casey, our furry kids.
2012 Forrest River Lexington 283ts
Toad, 2013 Subaru XV Crosstrek