This proverb relates to an old belief that witches would come out at night to throw stones at people’s houses and knock on their doors and windows to scare the inhabitants. However, if someone is accused of being a witch and their own house is attacked in the same way, it shows the irony of the situation. Essentially, it means that the hostile and malevolent actions believed to come from you can also be directed at you. This can be interpreted as “Do unto others as you would have them do unto you.”