When the kids were small, I needed a way to keep them out of my handloading stuff. I could not talk the wife out of a closet either. I solved the problem by buying a locking office cabinet about 4 ft wide X 6 ft high X 20 inches deep. It was made kind of light so I replaced one of the shelves with a 1" plywood sheld and used aluminum brackets to mount the shelf to the metal cabinet walls. The system worked well enough that 20 years later it is still in service. Still can not talk the wife out of a closet.