You beat me to it YogsVR4 - Sure I believe in UFOs, I've seen lots of flying things that I can't identify.
But I have seen absolutely no convincing (or even interesting) evidence for either spirits/ghosts/etc. or extraterrestrial aliens/ships/etc.
Although when I was about 6-8 years old, I did have some terrible nightmares about ghosts taking me away from my parents...
PS> There is one minor exeption to that, there is some interesting evidence of
possiblefossilized bacteria on mars - which would make it an extraterrestrial life-form.