I built a barn... more like a warehouse, actually. There had been a big building on the site before, mostly fallen down. I used all the same wood from the old building to rebuild the new one. When it was done, I was living in it (of course). It was always dark inside. Some college kids snuck in so I prowled around making freaky noises to scare them back out. They went and camped outside. So I went out and pretended to be a passerby. They told me about the "scary building" so I made a bet with them-- everyone put in $5 each, we all go inside, and the last one to come out gets the money. We all went inside and I walked to the middle of the floor and laid down and played like I was dead while they all made noises trying to scare each other.
I lay there a while thinking about what an easy way to make money this could be, but it would be better if I had some night vision goggles or something so I could make sure nobody else ever came in.