i dont, and dont think i ever will, not unless i see one for myself anyway.
though i did have a experience a few years ago i thought was strange and a ghost came to mind first. i filled up a bottle of water and put it by the side of my bed, i went to the toillet came back and the bottle was by the side of my bed but now it was totally empty with small beads of water runing down the sides, was only me in the house and nothing spilt on the floor etc. that freaked me out abit lol