So one of the things you have to prove if you want a 4Walls house is that you have title to your land.
Last month a family who thought they had title found out they did not. Their little plastic house was actually on land that was dedicated as a road. They got evicted. Now they have moved to a new plot, where they have title but do not have water. To dig a well, their friend, who must have some kind of electrical weirdness in his body, witched the well. He walked with a wire until the wire twisted. The twisting was a sign that water was below. They are digging now.
Check out the PBS video about water witching here.