Pretty much just the same thing Pidge said.

Your brain controls everything that happens and you are in control of your brain. If you believe that there's some magical spirit infront of you and you truely believe it then it's very possible for your brain to make you see what you want.

The amount of people who claim to see Jesus or some other God in a near death experience is incredible and it's simply just asphyxiation. The brain doesn't have enough oxygeon so it doesn't work properly and you see stuff that's messed up and you wouldn't normally see.

Coincidently enough though, everyone always sees their own God because they see what they want to see. Christians see Jesus, Islamics see Allah and so on.

PERSONALLY i dont belive in ghosts or anything like that
its just something that been thought of for so long
but no proof has been surfaced