This happened to my family about a year ago but I can remember it very clearly. It was the first of several paranormal things that after a time just went away but this one, the first, is the one that I remember the clearest.
Anyway, my brother and I were in our room when we heard scratching on our closed door. Our dog was in the room with us and nobody else was home, so it couldn't have been anyone else in our family. Not only that but we also heard no footfall in the hallway. If it was an earthly person we should have heard them.
To describe it, this was not mere scratching. It sounded as if a sharp fingernail was tracing out a symbol, perhaps one with a circle, I distinctly remember a circle, it was near the bottom of the door but it seemed very detailed because the scratching went on for a long time. I wonder now (especially because of what my family saw later) whether it was of the demonic nature. But it went on for a long time and then it just stopped. I didn't know if I should investigate what made that noise or not. But we both heard it clear as day.
My brother and I were almost paralyzed with fear because until then, we had both been skeptics. For some time after that, other things happened. My brother saw a tall, dark figure standing over me and watching me, like a shadow person. Then he saw it run past the top of the stairs. My dad saw it in the living room and in the basement my sister saw a woman in a long white dress. My dog sat in my room very still and stared at nothing into a very specific corner of my room. From that very corner one night I felt a presence that was very evil. There haven't been any weird things for a while now, but I am not a skeptic anymore. My brother and I refer to this entity as "our ghost", but we never found out what it truly was.