You know, maybe I should reconsider having my UPS at the bottom of a rack that contains one server in the middle with liquid CPU cooling... Or just add a liquid sensor between them somewhere perhaps.
Contrary to popular belief, one drop of water on the case of an electronic rarely breaks it. You do need to get a substantial amount inside the electronic to break it.
I remember building a water sensor kit as a kid and going to the bathtub to try sensing water and my mom rushed in and stopped me because I was putting electronics near water.
Unless the UPS catches fire, which would be bad.
You could put some absorbent or barrier material in between for paranoia. Don't need a whole new rack, although you could.