Yeah, it's the recessed lighting it'self. While it gives off light, the texture seems to become invisible, ergo causing a leak.

Also, button sounds got mixed up? Silly me. Fix't

Download link updated with new version, changed:

Fixed button sounds.
REAL lighting
Lifts now have sounds
No longer possible to fall out of the exit lift
No longer possible to skip the exit lift open trigger
Possible challenges (Except maybe the gold steps. I'm dreadful at the steps challenges, so I did my best, then guessed for a gold.)
A few other touch ups.