This is by no means a spectacular story (and I have read some wonderful ones on here!), but it was the most recent experience I've encountered and a bit creepy all the same.
About a month back, a friend and I were on our way to a party and stopped by our local Fred Meyer (in Bellingham, WA) to pick up some beer for our friend. We had just walked down the aisle, and faced with the dilemma of finding the brand our friend wanted, we spent a good few minutes pacing around and being unsuccessful in our endeavor.
Deciding to go to the grocery store across the street instead, I turned around to say something to my friend and right as I did, a bottle of beer on the third shelf up literally jumped out of the six-pack it resided in and rolled across the floor to our feet.
Startled, we both stared wide-eyed and silent; I would have assumed it had just fallen had I not witnessed it myself, and my friend quickly confirmed what I had seen. It looked like an invisible someone had lifted it straight up out of the pack and dropped it on the ground in front of the display case; it was a glass bottle and didn't break, so it obviously wasn't done with much force.
We both kind of laughed it off after a moment, until a Fred Meyer employee who had been about 5 feet away at the time came over to pick it up and we mentioned how strange it was. He told us straight-faced that it was just one of their ghosts; they have two of them in the store, apparently, and even have names for them! He told us weird things happen around the store quite frequently.
Needless to say, we got out of there pretty quickly after that!