The Sonoff S22 is a good candidate for reprogramming, with the bonus option that it supports external temperature+humidity sensors. You can definitely achieve

The Sonoff S22 is a good candidate for reprogramming, with the bonus option that it supports external temperature+humidity sensors. You can definitely achieve the same functionality cheaper with a ESP8266 breakout + shield, but this way you get a nice case that can just sit on a socket. https://www.aliexpress.com/item/Sonoff-S22-Smart-Wifi-Power-Socket-AU-CN-Plug-Wireless-Outlet-Socket-Support-Temperature-Humidity-Monitor/32824258981.html https://www.aliexpress.com/item/Sonoff-S22-Smart-Wifi-Power-... https://github.com/arendst/Sonoff-Tasmota/issues/627 https://github.com/arendst/Sonoff-Tasmota/issues/627