Anybody remember seeing an episode of Family Ties where the father shows a magic trick to the family by putting one of the girls in a box and making her disappear, but when he tries to bring her back, she doesn't come back, to which we then see "to be continued"? I recall seeing this episode once, wasn't able to watch the next day to see what happened next, and can't remember what else happened in the episode (I also don't recall which girl did the trick).
I've recently been looking at a Family Ties episode guide looking for multi-part episodes and then watching some on Daily Motion (just watching part 1 and skipping straight to the ending), with no luck (I haven't tried them all, I have ommitted ones that I figured wouldn't be it.... Or maybe I'm really wrong). At first I thought it might be the episode "It's My Party", which has the youngest one run out on her own party with her new popular friends, which does seem like it - the trick could have been for the party, the girl could have not come back because she wanted to escape, but I see that it's not that one.
Back when I saw that, I thought that the daughter who did the trick really did disappear and that they really had trouble bringing her back.