Anything supernatural is by definition not actually real. If it were, it would be natural.Picture, videos, and thousand of eye witness accounts yea OK. What do you want to go out and catch a ghost in a cage? If you don't see it doesn't mean it isn't there.
why the hell can't the supernatural be an explanation itself? The supernatural is science. It's just something we don't understand ATM and your making it seem like magic at a kids party.
So, if there were to be actual evidence (and an actual definition, lol) for 'ghosts' then they would be of the natural world.
And the fact remains that there is no reproducible unfalsifiable evidence for ghosts out there.