Allah Ta'ala knows best, but I seriously doubt it was Micheal Jackson or his ghost. It could have been a demon, as someone mentioned above. But in reality, this really does not concern us in any way or matter. The topic is idle and will do us no good. Every day millions of people die, and millions of people are born. Some are popular, some are not. Some are rich, some are poor. It's whatever Allah Ta'ala has decreed for us in this world. Otherwise, we are all equal, and our ultimate success is in one standard. That standard is the level of our Imaan. It does not matter if one is short or fat, hollywood or bollywood. The test is the same for us all. Allah make it easy for us all!