There are already some solutions around that try to address this on a consumer level. I recently watched a teardown for a piece of test gear that utilizes frequencies injected directly to the mains supply in order to control home hot-water heaters in Australia[0].
That's the great thing about standards -- there are so many to choose from!
That's the great thing about standards -- there are so many to choose from!
[0]: https://www.youtube.com/watch?v=Po4b7JhpxKQ