A filing cabinet made of cardboard. I don't know what they were trying to accomplish when they made these things up.
The only time I ever ran into one of these things was when I used to work for a computer store. The store was founded by two brothers, one of whome had moved on to greener pa$ture$. For some strange reason his office was left exactly as he left it, even though he had obviously been gone for years before I took the position, though we did use it to store garbage (actual garbage garbage, not metaphorical garbage).
The material that had been left in the office included a digital rainbow computer, a rack of thick books which comprised the assembly code for a dental clinic management program (I don't know, dont' ask), a little man figure with a beard which was both a lamp and a radio, and a cardboard filing cabinet.
The filing cabinet had completely collapsed under its own weight and hadn't been disturbed since the brother had left the computer store.
What I can't figure out is why anyone would make a filing cabinet out of cardboard. Any fool knows that paper is very heavy when it is found in abundance and that a filing cabinet made from card board has no chance in hell of maintaining its structural integrity under an even parital load.
Come to think of it I once found a briefcase there with nothing but a broken barometer in it once. That was a weird place.