[Afforess]

There are several services of varying levels of service, but honestly it's not that hard to write up a small script to fire off an email to get you to turn off the switch for a month. After multiple failures it assumes you are dead and sends a payload email to a trusted friend.

You can easily prepay up a good sum on most hosts, aws, digital ocean, etc. plenty of good low-cost mail apis too, like mailgun.