I stayed at a house like this in the Netherlands and it was terrifying. I saw a young girl walking around. The same knocking at the door...the last day we didn’t answer the knocking because we were used to it, and finally went and it was actually the police knocking. They had come because the house alarm had been triggered. They said it was from doors opening, but then the doors had closed so they figured we had made a mistake. We, and no one, had been home at the time!!! So something was opening and closing doors while we were out. No wind, no animals...I was so happy it was my last day!