[zaarn]

This could still be addressed by not putting the wifi part of the doorbell into the doorbell itself or alternatively using something like LoRaWAN where at worst someone could compromise the device keys (which you can reprovision) so your Wifi isn't compromised at all.

Another solution is to use a second gateway inside the house that manages the Wifi part and secure communication with the doorbell via short range radio.

[labawi]

Or you could use a dedicated SSID (vlan) with AP client isolation enabled.