In Germany, Freiburg, there is (or was) a strange public agency: they investigated about "ghosts". If anybody in the general public has a problem with strange phenomena, he can call this agency and ask for advice. It's really true.
I saw a film about them in German TV.
For me it was extremly interesting, because i had something like a noisy ghoast (poltergeist) that time. Three or five times a day something fell down to the ground without apparent reason. Once even my big crystal ball (it was a wedding gift) fell from the board down on the bed, on the pillow where i slept... Fortunately no person was in that bed in that moment.
So in the film the chief of this agency was asked if he believes in ghosts. He answered there is something without doubt. But it seemed to him that this "something" is created by the minds. (Sounds buddhist, doesn't it?) Families who suffer from ghost-phenomena have some unspoken hidden problems. And the best remedy against ghosts would be to speak out and work on this unconcious problems. Often this are painful things that happened in the past, now hidden in order to prevent from pain...
Regarding the falling crystal ball I was thinking about my poltergeist in this way "What kind of painfull occurence may i have blocked?"
Looking at it in this light the answer was extremely simple. Immediately i had to cry and to admit i have to work on this, talk about it, think of it - in order to be honest with myself and others...
The poltergeist vanished immediatly.
But by the way: i do believe and experience buddhist spirits or so-called deities who are helpful and full of love and compassion. In my meditation i can see them and listen to them.