Sonoff devices don't do this out of the box, but with some basic equipment you can flash [open source firmware][1] on them and make them work even better than s

Sonoff devices don't do this out of the box, but with some basic equipment you can flash [open source firmware][1] on them and make them work even better than stock, and no packets leave the LAN. [1]: https://github.com/arendst/Tasmota https://github.com/arendst/Tasmota