I have one of those duplex outlets in the house. It takes 2 hots, a neutral, and a ground. The 120V portion is internally connected to one of the hots on the 240V outlet.
Is that set of stairs portable? That is, not attached to the building? Maybe this is in a school room (audiotorium) with a stage, and the kids in the wood shop made this to give easy access to get on the stage from the audience area? Then it would be the equivalent to furnature, like a bookcase that sits in front of an outlet, and thus not a violation?
