My house has the exact same shadow people. My daughter has seen many of them, mostly they are at a doorway and she can see them peering around the corner or they stick their hand out.
I've personally seen a full body shadowy person in the middle of the night. It was all black with white spots, kind like looking at the night sky.
They never done anything or seem to have any ill intent.

You still see these dark shadows after 4 years ?