Years ago when I was in middle school, our class was lucky enough to take a trip to Rock Eagle in Eatonville, GA a large nature retreat center. It gets its name from the Eagle structure at the top of a hill believed to have been made by Native Americans upto 2,000 years ago. As with any type of retreat a good part of our trip involved nature activities: trust exercises, tugs of war, storytelling outdoors, and hikes (daytime and nighttime).
One fine evening we trekked up to see the Rock Eagle structure itself. We were a large group, and while it was very dark it wasn't too scary. The group consisted of probably about 40 people. I was somewhere in the middle of the group though separated from the first and second chunks of people. I was walking with a classmate to my right.
I could feel the warmth of another person as we proceeded wordlessly. I saw through my periphery, a boy my age holding a knapsack on a stick. Stunned, I turned to my right and there was nothing there.
It was my first and only encounter with what I think was a ghost.