Many years ago I used to go to a brasserie on my lunch break so I got to know the staff quite well. They told me they thought they had a ghost there - they decided he was a little boy called George. I can't remember all the things they told me that George did, but there was a basement store room which they all hated having to go to and there were other odd things late at night just as they were about to lock up.
Actually, I do recall one thing they mentioned. Anything child related - high chairs, colouring paper and crayons were the things that were always moved/strewn around overnight when the place was empty.
One day I'd arrived early lunchtime and there was only the manager and I there. He served me and went off to a back room to do something. I was sitting up at the bar doing a crossword. Struggling to think of an answer I was gazing rather absently towards the rear of the bar at the soft drinks shelves. Suddenly a whole row of bottles came flying off the shelf, not all together, but in sequence as though a child had run past with an outstretched hand to push all the bottles off the shelf, which landed on the floor with a resounding crash.
The manager came haring back round the corner and said "bloody hell, what was that? Are you alright?" I just pointed at all the bottles lying on the floor behind the bar. He and I both looked at the bottles and then up at each other and both said simultaneously "George!".
Yes, I guess there are rational explanations - but it was weird.