Yellow jackets all die when hit with hard freezing temperatures of winter, except for the queen, who leaves and does not return to the hive. However, yellow jackets could stumble into your home for months, if not all winter, because the warmth of your house keeps them alive. Commercial wasp and hornet spray should not harm your family, but the wall’s construction could block the insecticide from reaching the nest effectively. You may need a pest control company. Treat sooner rather than later. The longer the hive population builds, the bigger the resulting mass of dead organic matter, which in turn will attract insects that feed on it.