Most people don’t give too much thought to what’s behind their walls. Yet every time you flip a light switch or use your toaster, you are drawing on your home’s internal wiring—and that can cause big problems if your wiring is old or damaged. In fact, overloading an older home’s wiring can spark a fire. Home electrical problems start an estimated 53,600 fires each year, according to the Electrical Safety Foundation International. These fires cause more than 500 deaths and 1,400 injuries, and account for more than $1.4 billion in property damage. Many home electrical fires, however, can be prevented if you’re able to recognize and address a few common warning signs.