Press and hold the silence/hush button if the alarm is sounding
If it is a hardwired alarm, switch off the circuit breaker for that alarm
If it is battery-powered, remove the battery
If it has a sealed backup battery, disconnect power at the breaker
Twist the alarm counterclockwise and remove it from the mounting bracket if needed
Unplug the power connector if the unit has one
Reinstall the battery or restore power after the issue is resolved
Replace the alarm immediately if it is malfunctioning or expired