The Norwalk Fire Department is urging residents to make a simple change to their house that could save their life.The Fire Marshall?s office is warning residents to display their house number or pay a price. Fire officials say having proper signage on the home is a city ordinance. They also say a clearly displayed number can mean the difference between life and death in an emergency situation. Officials say all too often when responding to an emergency, they are left searching for a hidden or missing house number.The Fire Marshall says the department will begin to crack down on those not following the law. The number must be at least 3 inches in length, and must be clear to read both day and night. They also say if the house is more than 50 feet from the street the number should be posted on a mailbox or a sign that can be seen by traffic either way.