Not spooky, just stupid.
When my friend and I were 14, we made a Ouija board out of paper and Scrabble letters. We were both moving the glass, spelling out stupid words and both decided to lift our hands off at the same time to see if it moved on it's own.
The instant we did, a lorry horn blasted from the busy road outside her house and we both jumped out of our skins. We threw our home-made spirit board in a cupboard and went downstairs to be around the grown ups.
Nothing to do with séances or spirit boards, But something serious happened to me 14 years ago when I was pregnant, and I've never found out what it was. I opened up a food cupboard door, and a ball of bright white light flew straight at my face, fast enough (and realistic enough) to make me stumble backwards and duck my head out the way. The person I was with saw it too. We looked around to see if it was a bug or something but there was nothing there. It was in winter too, so the chances of it being a flying insect was low. Never happened again and I have no idea what it was.