Most mini-storage units are metal buildings on cement slabs. The units open out into the weather. The cement floors draw moisture. Most don’t have any lights. People have to put blocks or pallets down so their stored items don’t get wet or mildew.
Problem solved! Now you can rent a storage unit with an indoor entrance, a solid wood floor on joists, and with a light so you can mess with your stuff to your heart’s content! Imagine that! Finally a place you can feel more comfortable about storing those boxes filled with paper or that piece of furniture that that was a little too nice to put in a regular storage unit.