So I was looking to install a ceiling fan in one of our rooms. I need to replace the pan, but that's no problem. What is a problem is that the existing pan has two romexes going into it, and they appear to be on different circuits. Worse yet, the neutral from one is tied to the hot on the other. WTF? Anyone have any clue why this might be like this, if it's safe, and how to deal with it?

I'm probably going to call an electrician, but I'm really curious.

Will post picture of wires later.

I am the Doctor, and THIS... is my SPOON!