I had an experience once with what people call a shadow person, I could explain it in great detail because the experience lasted for about an hour and a half, I was 14, I had a habit of sneaking out of the house. Forgive the Drawing, I can actually draw a lot better than this, But for the Sake of posts and something like this, I figured something Quick would work.
So, I was watching Tv that night, I was 14, At this time, Old late shows like Johnny Carson were still on TV, I Thought my Dad was watching me trying to catch me sneaking out of the house, After a while, I forgot the figure was there. Later on, I noticed it again, Still assuming it was my dad I told it that it could go away now, I wasn't sneaking out that night. It gave no kind of answer, I eventually yelled at it and heard my father from another room in the house. I was frightened and I had two choices, I could jump out of a closed window and probably get cut on the glass and die, Or Rush at it and try to tackle it thinking Dad would come running when he heard the commotion.
I don't know why I could see it, Maybe it had something to do with the light glaring at an angle on it from the Tv? But, I rushed it, When I got right up on it, I could see it wasn't people, It was like a three-dimensional shadow, I could even see through it. Almost face to face, I yelled, What are you!! It was then that it realized I was addressing it. Like it was almost certain I couldn't see it or something. It took an alarmed stance and ran, As it ran it used open doorways, But disregarded furniture like the refrigerator like it wasn't even there, passing through those objects.
Till this day, I've never seen anything else like it, I still don't know what it was.
All I can say is, I got this feeling from it, Like it was scary or like it had ominous intentions, But, It never did harm me or my family, So I can't really say they are evil. More than anything else, It was just observing me, I don't really know why.
I have later in life came to think that maybe they are beings from another dimension or reality and the reason they look like shadows or ghosts is simply that their means of observing us simply won't allow them to physically manifest here. I honestly Still don't know what it was, or if my theory is even valid about them being from somewhere else. I honestly just know, I saw something that was see-through, could acknowledge that I was addressing it and it could display alarm, Overall, It's reactions and movements, seemed very human-like.