You can’t gauge the lifetime of a fire door like you could, say, an engine. Fire doors should be checked at least once every six months to ensure there are no signs of degradation like leaks, holes, water damage, termite damage, or anything else that might compromise the functionality of the door’s fire resistance. Check your smoke detectors while you’re at it.

Yes, a faulty or broken light switch can be a serious fire hazard. Malfunctioning switches, often due to loose connections, exposed wiring, or overheating, can cause sparking or arcing. If you hear a crackling, popping, or hissing sound when you use the switch, it indicates live electricity arcing inside, which is a significant hazard that can ignite nearby flammable materials. If you suspect your light switch is faulty, turn off the power to that circuit at the breaker and contact a qualified electrician to remedy 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. 

Your smoke detector might be too high in some homes or circumstances to reach yourself. If you feel unsafe getting on a ladder to replace your hardwired smoke detector, call a licensed electrician or local handyman to knock this project off your to-do list. If you have a battery-operated smoke detector, your local fire department can change the batteries or help you replace the detector—just make sure you call the non-emergency number.

In any case, do not let this project go unresolved, as it could turn into a huge safety issue.