It might have to do with the fact that thriller has more to do with the supernatural. Ghost tells more about how Evan Chandler tried to put MJ behind bars (as horrible as that was... Poor Michael). That may be the case.
hmm..good point.I think in Thriller because it's more about zombies,it has some scary effects and it's like about after death
In Ghosts is amazing and it has super effects but i think you don't get scared because he is too sexy in this movie to be scary XD!!! lol