> There is a chance you could do here what powerline adapters do, and use the ground wire to communicate. But they are notoriously inconsistent and there's any

> There is a chance you could do here what powerline adapters do, and use the ground wire to communicate. But they are notoriously inconsistent and there's any number of reasons it wouldn't work This is exactly how Insteon works in conjunction with a wireless mesh. I'm extremely happy with my Insteon setup -- it's just a matter of replacing light switches and outlets with a bit of re-wiring on 3-wire switches (no new wires to run, just bypassing one of the switches so only one controls the light). The Insteon-branded hub is fine for a few light switches, but if you're doing a whole house and need something that can handle more complex configuration I would go for an ISY994 controller (don't know if anything newer exists but it's been rock solid for the last 5 years). All that said, it was expensive and probably not worth it. I spent $4k on a somewhat large house and I was able to justify it as a learning experience for in-home IoT device use cases -- but I'm not sure there's much benefit to doing a whole house with it over just a couple rooms.