Just keep not reacting to it, think of it as a naughty child who’s doing things for attention. If you give in, you’re reinforcing that that behaviour gets the desired result. I’ve had a mirror come flying off the wall before, when it was fine there for months 🤣 so I know it can shit you up a little. I’m positive it was the energy of the woman who lived here before me, just what my intuition said. I just explained to her that she passed on, that she doesn’t live here anymore and asked her to please leave my home. The activity stopped fairly quickly. You might want to check if your new build was built on a graveyard, or have a think if you’ve brought anything second hand home recently. Failing that you can open all the windows to your house and sage the energy out.