I have seen a few of them in my lifetime.
When I was about 6 was the first I remember, a lady who used to stand in our hallway in the middle of the night. I never found out who she was or what she wanted, and even at that age I figured out she wasn't a regular person. And of course my folks didn't believe me, what's new?
Then there was a ghost I hit with my car!
I was driving alone and turned my head momentarily to look out the side window, and when I turned back a young man traveling with a backpack was standing right in front of my car! My headlights were right on his middle as he was just a few feet from me. I slammed on the breaks but it was of no use anyway, I "hit" him but actually drove through him. Cars behind me were honking, swerving to pass me, etc. I stopped but could see no one, and no one else stopped. There just wasn't anybody there. I managed to drive the rest of the way home, although my legs were like jello and I couldn't stop crying. When I reached home I didn't know whether to call 911 or dad, so I called dad! Good old dad, he helped me get calm and not lose my mind. He actually had me go out and inspect the hood of the car for dents, blood, etc. any evidence of having hit someone. Also, he asked if I felt a bump which I had not. So he concluded it must be a ghost or an angel, either someone lost or someone telling me to pay attention to the road!!
Then a couple years ago I saw one in Walmart! Ha ha, of all places. This is a long story, so I will shorten it up. I saw an old man who was staring at me, and it scared me because he looked so scared, upset, discheveled. He looked perfectly solid except that he was floating, not walking. I turned away to make him go away but when I turned back he was still staring at me. He seemed to leave after a minute. We spent a long time there at Walmart, with eye appt's at the Vision Center and picking out glasses, getting the kids McDonald's (inside the store), and then finally going about our shopping. While we were down the laundry hamper aisle I turned to look at my husband who was at the end of the aisle asking me something, when I saw the same old man walk by still staring at me! He was still floating, but what I noticed this time was that his image was superimposed over that of everything else around him. It appeared visually that he "fit" into the picture but actually it was an impossible fit as he should technically have been bumping into the people around him, which he didn't. It is hard to explain but that's the best I can do.
This was before I knew more about spirits and the non-physical world like I do now. I didn't know what to do, like as far as retrievals go and such. I wish I had been able to help the old guy, he really looked so scared himself.
I'll try to remember if there's any more stories. Thanks for letting me share!