Here’s a link to all the info on virtual switches:
For the custom event, is his a text or a push message?
One thing you could use (as long as the device and action are supported) is Rule Machine.
It is extremely popular on here and allows you to configure Rules which are comprised of Triggers, Conditions, and Actions (you can set up multiple conditions and actions for different events).
Using Rule Machine you could absolutely set up the Rule to have an action of Turning On a Virtual Switch as well as Sending a Text Message. You could also set up Push Notifications.