Ghost hand!

Not a great photo thats for sure but weathers been so poor I just haven't been able to go out.

I just found out that my D3100 does have a form of multiple exposure, so I have been playing around with it. It's actually an image overlay setting that you can do in the camera settings menu. Just got this effect by using bulb mode, keeping my hand still in one shot for a short exposure, and in the next moving it around for a slightly longer exposure.
For those who don't know, multiple exposures are the classic method of taking "ghost" photography, back in the good ol days of film photography that would take two images of the same place, one with a person in it, one without, but not wind on the film, thus putting two (or more) exposures on one shot. that is where a vast majority of ghost photos come from.
Still, I'm willing to believe not all of them are fake :)