Random un-useable object?

[Cranky Old Man]

I don't think im the only one who found a lever but never found where to use it!
does anyone know what to do with it?

Either you mean the spinning lever, which you use to replace the one that breaks in the cistern machine room (which you don't have to use if you prop the door) or you mean the iron bar which you don't need to use in the prison.