Yes, an electrical fire can start even if nothing is plugged into an outlet. While a correctly functioning outlet poses no risk, a fire can be caused by faulty wiring, damaged outlet components, an overloaded circuit, or other electrical problems hidden behind the walls. If you suspect a fault, immediately turn off the circuit breaker and contact a professional electrician to diagnose and repair the issue.

Although you can put a smoke detector on a shelf, the NFPA recommends mounting one on the ceiling or a wall (within 12 inches of the ceiling). If you place your smoke alarm on a shelf, ensure it’s away from drafty, damp, or dusty areas and not near cooking appliances, heat sources, or fluorescent lights.

Signs that your dryer is about to catch fire include a burning smell or the dryer and the clothes getting hotter than usual. If this happens, turn the dryer off immediately and call a repair professional. Another less urgent sign is that your clothes are taking longer to dry than normal. If this is the case, check the lint trap, vent, and duct to make sure they are all clean. If they are, you may need to call a pro to find the source of the issue.

The National Fire Protection Association (NFPA) says you can place smoke detectors on either the ceiling or the wall, depending on the setup of your room. Since smoke rises, the ceiling makes sense, but if you go with a wall mounting, the alarm should be installed high up—no less than 12 inches from the ceiling.