This took place when I was about 9 or 10 years old at my (at the time) closest friend, Yani's house. We went to school together and neither of us to my knowledge had ever seen or heard anything that might be considered a ghost (or any other paranormal entity). I was staying the night there and we has just recently gone to bed for the night. I was laying on the floor while my friend was in his bed.
I hadn't fallen asleep and I heard my friend say "look look!" I usually sleep on my side so I turned over and saw a vaguely humanoid, semi-transparent, green figure just hovering in front of the door. It almost seemed like it had the consistency of an egg white in that I could only partially see through it to the door. I also recall that the center of the being looked more solid, then became more transparent around the parameter of its form. I was pretty freaked out and I remember Yani saying "do you see it?" I could tell he was scared as was I. The green figure didn't make any sound but just floated there, sort of moving in place. I don't remember what I said to Yani or what I did then, but I'm pretty sure that I covered my head with the blanket. His mother didn't seem like she believed us when we told her but the experience was pretty vivid.
It's been many years since that happened and I'm no longer in contact with Yani so it's tough to put down all of the details about it now.