Most large SCOM management groups have lots of management packs and lots of monitored computers. Invariably this means that there are lots of event collection rules collecting event data and storing it in the Ops database and the datawarehouse.
It is good practice to review these periodically as you can prevent your scom datawarehouse from unnecessary bloat by over collection of this event data that you never use.
Run the following SQL query on your Operations database to view the top 20 event collections
SELECT top 20 Number as EventID, COUNT(*) AS TotalEvents, Publishername as EventSource
FROM EventAllView eav with (nolock)
GROUP BY Number, Publishername
ORDER BY TotalEvents DESC
You can then setup an Event View for the event you want to stop in the My Workspace pane of your scom console. Select New View, Event View and enter the event id. You can use this view to create an override to disable the event collection of your choice.