Determine the cause of the alarm. You can't just shrug off the annoying howling without checking what it is as absolutely false call – a rare phenomenon. Perhaps in some premises there is smoke or really fire occurred. When Troubleshooting why an alarm silenced itself. Ventilate the room, check all possible points of emergence of a fire, including electrical wiring.
If the alarm is still triggered without any reason, disabling depends on its type. The easiest way is to remove the sensor in the flat battery. Without the battery the alarm will turn into just a kind of decoration on the ceiling. But remember that in this case, you will be left without protection if there is a real fire.
If the building has a centralized control panel, unplug the siren with him. Sometimes you should dial the code, known only to the people who are responsible for fire safety organization, so refer to them.
If the sensors were clogged with dust due to e.g. construction works, disable them, carefully dismantling and wiping with a cotton swab with alcohol. After eliminating the cause of the problem the siren will fall silent.
If you for some reason need to temporarily disable the fire alarm in one room, for example, in the Dorm or in the server, cover the sensor with tape or wrap with foil, then closed with a rubber band. In this case it doesn't work neither smoke, nor the temperature increase.
The most radical method – to eat the wires to the sensor. The alarm will stop, but will be useless for further use until repaired. So, to disable the alarm but it is better still to understand the reason for its triggering. Because it affects the safety of the whole building, and possibly your life.