I managed to have a sim die of death by laughter (if anyone is interested, the resulting playable ghost is the Roman Centurion downloadable from my gallery ↓), thanks to the wishing well from the romantic garden pack. The well cursed my Sim with an intense hysterical moodlet that lasted for a few hours. It was a chance too good to be wasted, since I had unsuccessfully tried to kill a Sim by laughter for a while, so I immediately added to that family a clown with the fulfilled joke star aspiration that I already had in my gallery. The clown told my hysterical sim a few jokes and that finished him off.
Unfortunately the wishing well curses are pretty random, so I don't know how frequently you'd have to try to trigger this particular one. But it was certainly very effective.