In 2005 my oldest daughter was living in Florence while attending college at Kent State. She was there doing arts and fashion classes and lived there for about 6 months. My wife and I and my youngest daughter traveled to Florence to spend a couple of weeks with her and see the sights. It is quite possibly the most beautiful city I've ever encountered.
One morning the four of us were walking to pick up tickets for the Uffizi Gallery. At some point the sidewalk narrowed to the point we could only walk in single file. I was the last in line. All of a sudden the first person in line stopped, turned and looked backwards and then the three of us behind in succession did the same. Something had run between our legs; something invisible. It was the oddest thing - it didn't feel like wind, it felt like it had substance; I could feel it brush my legs as it ran through. It wasn't at all frightening to any of us but very strange. Being an engineer but not necessarily a skeptic, I began to search my mind for some sort of explanation. I looked to see if there was a sewer grate, or manhole or anything near. There wasn't. We discussed it at to this day we all remember how unexplainably weird it was, like an invisible dog or something. I still think about it. Perhaps it was some sort of magnetic field caused somehow by underground electric cables. I don't know.
I've wanted to post this for some years now and I'm finally getting around to it. Perhaps someone else has experienced the same phenomenon. I do know that Florence is reputably haunted by all manner of spirits and that it is an ancient city, possibly built on Etruscan ruins. Perhaps all the ancient stone and history still harbors some kind of energy from the past; shades and movements that occasionally under the right circumstances reveal themselves to us.
Thanks so much for your time.