the right question is not if you believe in ghost and spirit, but whether it is a fact or not that there are ghost and spirit.
of course this begs the question, what is a fact and how you know etc. For example is a fact something you see or something you feel? Can things unseen be facts? Some say definitely not, but then who has seen an atom, if there is at all such a thing as an atom.
I believe only what is fact, and nothing more, nothing less. (and the fact could not care less if I don't, the fact remains a fact.)