The most likely reason that cause fire alarm randomly going off is that people forget to change the batteries in fire alarm devices regularly. The second most common reason is food preparation. Also, sensors set close to the fireplaces can be sensitive to smoke.

National Fire Alarm and Signaling Code® NFPA 72 provides the latest safety provisions to meet society's changing fire detection, signaling, and emergency communications demands.

Dense water vapor is like humidity when it comes to triggering false alarms. When you take a shower or boil water on the stove, smoke detectors can sense the steam and sound the alarm. Make sure you ventilate your bathroom and kitchen properly to prevent this.

The four most common detectors are ionisation, photoelectric, combination ionisation/photoelectric, and heat. All smoke detectors sound an alarm, when they identify smoke, to notify a building's occupants. What differentiates these detectors from one another is the way that they detect smoke.