Dear Boss,
I have been cleaning everyday with diligent duty, as per our agreement. However I have noticed an alarming amount of unscrupulous folks coming through your grate in the maintenance closet. I propose you put a lock on the tunnel grate, or at the least the maintenance closet, and give me a key for safekeeping. I've had to replace I don't know how many buckets of clean water because people get in there and get into it. I'm already missing near a dozen towels as well.
Signed, Froppin the mop boy.