Had a leak show up in my RV during the weekend deluge while we were camping, tracked it back to the fact that the lighted grab handle was installed upside down, not to mention they depended on the cheap sticky stuff to stop it from leaking. Had to a drill a hole to move the wiring to the top where it belongs, (reversing the handle). Resealed the handle with RV sealant when reinstalling.
Basically what happened was water was running down the handle into the mount, as well as coming in around the mount, filling it up, then running in the wiring hole. From the blistered paint and water marks it has probably been leaking since it left the factory, it just took 3" of steady rain for it to fill up and start leaking inside.