On the original Art Fleming Jeopardy!, ever see an answer card disappear?
The original board had slots which contained up to 3 cards: the numeric dollar value, the Daily Double card if present, the answer, and behind all them, a plain blue space. We always saw them lift up the number and DD card. (Thanks goes to Randy West, who recently described seeing this done back in the day!) But I only remember once seeing the answer card lift up to reveal the blank space.
One time on Fleming J! (I used to watch it every day at noon before leaving for afternoon kindergarten) the stage hand in the back accidentally picked up both the number AND the answer card! Faced with a blank space, the stage hand hastily slid the answer back in place -- and in the process I saw some (gasp!) human fingers at the top of the card! Up until then I was not sure how the board worked, imagining some Rube-Goldberg type system with motors, levers, gears and/or magnets to lift up the cards. I also used to imagine "the other side" of the J! board as being some sort of dark, dungeon-like enclosed space.
The only time I ever saw the backside of a gameshow prop was when the Today Show had (I think) Cliff Hangers from TPiR. Lots of signatures scrawled back there.
On still another occasion, someone walked up to Fleming right in the middle of the show to tell him something (?), and this person was openly carrying one of the answer cards!
I never noticed an answer disappearing on Trebek's J!, but they probably timed the camera angles so that never happened. Nor did I notice, after some 10+ years into the run, any categories disappearing. Originally, the categories were physically posted there, and all they did was "turn off the light" when a category was exhausted. Now, of course, they blank the monitor that displayed the category -- something I've found questionable, since I sometimes wonder "what was that category again?" after the last answer is displayed.
