Someone sell raw lots cheap. Usually 100 dollars down and low payments. No paved roads. People who buy often can't afford lights, septic or water if even in an area that is covered. Usually they just pop up and they want services and the county has to eventually step in and run services. Sometimes it multiple family living. Small houses, cars, buses and lean-tos often the dwelling. Crime tends to run higher too.
Sad situation for anyone to be living in. I had heard a couple of years ago about sponsering a family that was down on their luck and living in such conditions. Disease and high crime was their worst enemy. It was heartbreaking to read about it.