What are the chances of getting cancer from second hand smoking?

Too high. Some government and pop claims that second-hand smoke produces 50, 000 deaths yearly in the usa are obviously false (founded on crazy assumptions), but the risk is real; the best papers say 3000-5000 deaths mostly lung cancers in the spouses of heavy smokers. A smoky home is abusive to children and a smoky workplace for adults. You have a right not to be exposed. Good luck.