A lot of people use storage facilities to hold their seasonal items, junk, or treasures when they do not have room in their houses. Sometimes, they forget to pay the fee or never return for their things at all. After a certain period, the abandoned unit will be sold off.
Source: Relatively Interesting
The storage unit will be up for bid in an auction and the winner own whatever is in the storage unit and clear it out. When one man found a lot of cash in the storage unit he won, he thought he hit the jackpot. It turned out it was the start of a living nightmare.