For me it is all hokum.
I have been to ghost hunts where we have even done the ouija boards, deveined with crystals and stood in the dark calling for the spirits to answer.
Some people there were convinced there were spirits present. The tab curtains moved and swayed on their own, the bump from the room above couldn't have been any living person, the ouija board moved to spell out a message, the camera set up outside picked up floating lights.
Well, the curtains swayed because the draft from the back door is notorious and for some reason it swirls up and over the tabs before coming down the other side of the stage. So you don't really feel it sitting on the stage.
When you are in a 300 year old poorly maintained building the place creeks and groans all the time. You just notice it more in the dead of night.
For some inexplicable reason the ouija answered a made up random question I asked. !! Did I influence the answer or did one of the mediums?
When we went out to look at where the floaters were there was a lot of fluffy tree pollen wafting about catching and occasionally reflecting the light from the moon and security lights.
But over half those present (mediums not withstanding) were convinced it had all been done by ghosts and spirits.
You only have to watch those brain game videos where it shows your brain believes something is true when in fact it isn't. Because the brain compensates. Those that have 'seen things' believe they have seen them but it doesn't mean it is true.
Having said that I do think things happen that AT PRESENT we don't understand how they happen. Given time almost everything will be known. We might get very bored by then not having much to ponder but I think it will be a long time coming lol