Shit always happens when you least expect it. Reminds me of a side job I did recently for a friend of a friend of a friend. Replace hot water heater. Piece of cake right? Electric too which is really easy. So I speak to them on the phone and give them a very cheap price to install it/remove the bad one. Tell them to purchase whatever one they want at HomeDespot/Lowes just make sure it is the same size and shape as the old one so it fits. I get there and it is in a back closet of a bed room in a double wide. Well that's a pain but not a big deal just move some furniture, drain water out window with a hose, done it before. Then I notice the rug is wet near the closet door. I open the door and there is mold, I mean massive mold everywhere. It is so bad the sheetrock is falling apart. Turns out the there is a leak that has been happening for quite a while, some idiot used a metal fitting with plastic piping. wtf. And the piping is all over the place, one section is a mistake that they apparently just tied in to another section instead of removing.
So I tell them they are going to need the whole thing gutted and much of the carpet ripped out to stop the mold. I offer a cheap price to do it, and this is a seriously rough job, mold sucks to deal with and can make you very sick if you don't take serious precautions They don't believe me, get pissed off at me, I mean wife is almost yelling at me. I say sorry dudes I'm out and leave. Two weeks later I get a call from the wife all nice as can be asking if I'm still interested, apparently they found out reality and that I offered them a very cheap price. I ended up not only gutting the closet but also removing the carpet in the whole room after showing them the mold growing under it, branching out from the door. Replaced with some vinyl faux wood flooring, pretty good stuff and I did it right with a moisture barrier. Also painted the whole room for a couple more hundred, all new bottom trim, etc. I actually made out pretty good after they realized they had to pony up real money.
You never know what you are getting into sometimes.