I was sitting in my rocking chair, reading--but not rocking--.
Suddenly, my chair started rocking me spontaneously. I staid sitting, as I certainly didn't want to start walking--and maybe fall down.
It was dark outside, and a kindly neighbor came over to ask me if I was OK, and I told him "yes", and thanked him. Then, when he left, I heard him stub his foot on a decorative rock I have surrounding a little garden.