What if my father-in-law has been living in my house?

Talk it over with your husband and let him talk to his parents. You can live at home, but your elders have to be like their elders. No, brothers can't negotiate a sum of money to rent a house with their parents and properly arrange their parents' food, clothing, housing and transportation. Only when you are a child can you live a small life with peace of mind. This situation is really helpless. After all, they are your husband's biological parents. They have nothing and no place to live. It will bring a lot of trouble in the future and can only be avoided. You can consider renting a house suitable for him outside and discuss it with him. After all, it is more appropriate for him not to go back.