I think it may have been released around 80s or 90s. The only scene I can remember involves two men in an elevator. One of them looks down at the elevator floor and realises its not there, and suddenly falls through it but somehow is able to hang onto the invisible floor with his hand. The other man (still standing as if nothing is wrong) begins to explain that he must use his imagination to make the floor "real" (if that makes sense?). Its abit vague and I don't exactly know if it pans out in that exact way, I just have the image of a man hanging onto an invisible elevator floor by his hand, does anyone have any ideas?