Annoying & somewhat intimidating

I was in our bedroom watching a show on the iPad. The whole time  Iwas watching it, from behind the attic door on the steps I heard someone or something tapping/stomping the steps. Also while I was watching the show I seen 3 dark shadows going back and forth in the bedroom itself. After the show was over and it was quiet, I once again heard the tapping, louder this time, followed by a girl's voice saying, "get out" very loud. I do not know for sure if it was in fact a girl or something imitating a girl because of the nature of whatever is here. The house has been quiet for quite awhile, but for some reason it chose tonight to start up again.