When i was growing up we were into ghosts.  I lived in a town called Brockton in Massachusetts.  It turns out it is part of whats called the “Bridgewater Triangle”- an area of Massachusetts with many strange events happening…including a ghost type aparation that was seen by police officers and affected their radio (this was in the 1970’s.).  We were into ghosts and often dide seance’s and ouiji board sessions in our dark dank basement that we grew to be afraid of.  mostly we just hear occasion creaks and step like sounds .  but one day when i was about 16 (almost the 80’s by that point) we were all watching tv in our living room-me , my mother and my two sisters.  Suddenly we saw the screen door being opened to the main door to the house–we could hear it being opened as well.  And then someone turned the knob to the main door in front of the screen door.  My mother was right there and immediately opened the door to see who it was …but no one.  nothing was there at all.  Either they ran away very quickly or…wel who knows.  it freaked us all out because we all saw it and couldnt explain it.  Later that night when my father came home from work and we were all asleep i guess the same thing happened to him-he told us the next morning without knowing of our story.  It could have been a prank or something but still that person had to run away very quickly.    Anyways just wanted to share.