Catalina Pet Hospital
The box may seem way too small or large, yet not seem to be a deciding factor for the cat. Some objects only have to be "box like" for the cats to choose them for their new lair: dresser or vanity drawers, linen shelves, baskets, sinks, etc.
Why do they choose these areas? Cats like the protection offered from being able to sleep in partially or totally hidden areas. Some nooks may be particularly comfortable if there is a blanket or towel to lay upon. Other spots may be extra snug, allowing the cat's body heat to radiate which makes it extra warm and cozy.
New boxes with new smells help alleviate boredom and can provide entertainment for the cat in an inexpensive way. In some cases, cats may be ill if they are spending too much time hiding in a cubby somewhere so make sure to keep track of your cats habits. Also, be careful of accidentally enclosing your cat into places like clothes dryers!