I think one of the neighbors brought spirits to our building

[Mystic Wanderer]

This is a pretty good short video about Shadow People.

Very good. 

I just hope all this paranormal talk doesn't open the door here again. I've been pretty good about keeping it shut for a couple of years, at least to the bad ghosties. 
I didn't see the shadow person described in the video that I saw. It was short, maybe 4ft tall and had wide shoulders. I only saw it's upper body because it was peering around the corner of the hallway at me with it's lower body hidden behind the wall. No eyes, just a black figure. 

Anyway, thanks for throwing that out here at almost bedtime @"guohua".  And Sweet Dreams to you too!