Hidden or Ghost alarm on MacOS, can't stop or silence, I found the solution

I can see where quitting the process would stop the alarm, but the process will start back up automatically and if the alarm is a repeated alarm, it will happen again. The Clock app is in your Application folder and you should be able to see the alarms that are set there.

Another way to get to your Notification when the alarm is going off on the Mac is to click on the Date and Time in the menu bar on the upper right. This will slide in your Notifications and should give you the option to stop the alarm.

1. Open Activity Monitor (keyboard shortcut apple-option-esc)
2. Search "notification"
3. Click on "NotificationCenter" to select it
4. Click the X with a circle around it in the top bar
5. Choose "Force Quit"

You will find that Notification Center will start back up, usually immediately. Any process that has a parent process of launchd will never let it be stopped. It will stop the current alert/notification, but will happen again when the next one is scheduled. The solution is to prevent the alarm in the first place and can be done by reviewing the alarms set in the Clock app or verify if the same thing happens when started up in Safe Mode. If it does not happen when started up in Safe Mode, then you have a process that launches on startup that is activating the alert. This can be identified as well.

Jeff_55 wrote:

That's just the standard Alarm window in the Clock app. That was part of my problem.

I couldn't see or open the Clock App to get to the alarms to cancel the one that was chiming.

This has happened a few times in the last year. Next time this happens (once a month?) I'll be extra careful to see if I can re-launch the Clock app although I'm fairly certain I tried that while looking around for a way to silence the thing.

You can try a SafeBoot Use safe mode on your Mac - Apple Support will sort many anomalies

Does a quick disk repair before it fully boots up, and certain system caches get cleared and rebuilt, third party system modifications and system accelerations are disabled.

Login and test. Reboot  as normal and test.  Caches get rebuilt automatically.

Open the Clock app in the Applications folder. Press Command+2. Remove any alarm settings listed.

Jeff_55 wrote:

I've looked here and through Google with no hits, but several times I've had alarms go off as set on my Mac, but there's nothing displayed so I can't cancel the alarm. After a lot of looking and experimenting I found the fix and thought I'd post it here to see if it helps anyone.

I went to Activity Monitor and used it to quit the Notification process. That stopped the alarm and brought up the Alarm app. Problem solved.

Has anyone else had this problem?

"Alarm app"...?

Never heard of it.

Is this third party you installed(?)