I personally am not sure if to believe in these or not since there is no evidence to support them. I once had a experience where I woke up in the middle of the night and noticed this white floating orb like mist at the end of my bed which I stared at for at least 30 seconds before it started floating towards me and the orb started to form this UGLY evil looking face at which freaked out. >_< I even screamed and looked away and it was gone.
I can maybe dismiss that as I wasn't fully awake, my family members have seen some weird stuff in the house, three people witnessed a baseball being levitated and thrown. I wasn't there so I cannot say for sure among other things.
What do you personally believe? Should we just blow all this off as mass hysteria?