A grease fire starts if hot cooking oil comes into contact with a heat source, such as an electric heating element or the flame on a gas range. Once the grease is ignited, it can be very difficult to put out. 

Wiring a light switch wrong can cause a fire if the incorrect wiring causes arcing, meaning the current jumps uncontrolled from one conductor to another. Loose wires or worn wires that are not repaired or replaced can cause arcing. If you’re not 100% sure you can do the job safely, don’t attempt to wire a light switch on your own.

Certified fire door inspectors should inspect fire doors. These professionals receive training to specifically assess the condition, functionality, and compliance of fire doors. They often hold credentials from groups like the Door and Hardware Institute (DHI) or the International Fire Door Inspector Association (IFDIA). While fire marshals won’t usually do hands-on inspections, they’ll check that doors are being maintained properly during routine safety audits. If a building relies on fire doors for code compliance, it needs someone who understands the details—the difference between a cosmetic issue and a safety failure—and standards to sign off with confidence.

A smoke alarm that beeps periodically, often every 30 to 60 seconds, usually indicates a low battery. The first step is to replace the battery. If this doesn't solve the problem, try resetting the alarm. However, beeping can also signal other issues, such as dust buildup in the sensors or the unit reaching the end of its life. Different beep patterns can mean different things; for example, multiple beeps might indicate an issue with a combination carbon monoxide detector, while a continuous, loud alarm means smoke has been detected. If a new battery doesn't stop the beeping, it's best to consult your alarm's manual, call a professional, or replace the unit.