Of course not! It will attract evil spirits! If this soothsayer doesn't mean to hurt you, it's a bit nonsense! When and where have you seen the plaque hanging on the roof? If you want to hang it, you should also hang it on the gate or nave. Think about it. What does the sign on the house look like?
It doesn't affect the neighbors, but he is right. This neighbor must have a good relationship with your family. He said that for your own good.