Alerts arriving unwanted and irrelevant

Question

I see iCal Alerts for events on an accessed calendar (my wife's, and it's a 'CalDav' Google Calendar) appearing on my screen whether her calendar is selected for display on my screen or not.
My iCal also mirrors my Google Calendar without this Alert intrusion.  I see no setting that would trigger this behaviour. 
This is years-old behaviour...
I have 'repaired permissions' for my Mac and saw no likely 'calendar' log entries.
In case it of any value, the iCalExternalSync.plist says:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<true/>
</plist>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<string>1397828E-A2B8-472C-995D-021632E1A17D</string>
</plist>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<real>3.509144e+08</real>
</plist>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<integer>1123</integer>
</plist>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<false/>
</plist>
Any idea what I can do to stop this behaviour, please?

Answer 1

Can you be more specific on what kind of alerts you would like to disable?
First things first:
If you would like to disable an alert you find in the console you can right click on it => override => for all objects of the specific class => enable = false
If you would like to disable repeated alerts you can run the "most common alerts" report located at Microsoft Generic report library => most common alerts
You can start from the top down and tackle the most common alerts to disable or finetune the thresholds...
If you need more assistance please do not hesitate to reply.
It's doing common things uncommonly well that brings succes.