My plea / request : Make a home assistant a DROP IN replacement for a standard light switch. It has power, its adds functionality from the get-go (smart lighting), it’s placed in a convenient position for the room and no extra wires etc required.
Look at Shelly light switches.
You've misunderstood what they're asking for. They're asking for Home Assistant hardware (microphone, speaker, wifi) that, instead of being a standalone box taking up space on the counter/table/etc, fits into the hole in the hall where they currently have a lightswitch.
I guess I did misunderstand, because that request seems strange to me. I’m assuming they have more than one switch. Which one should have Home Assistant on it? Seems like an odd deployment strategy. A pi isn’t that big..
Not OP but if I have to have a CPU and microphone for voice commands anyway it doesn’t sound crazy to throw a whole pi/relay node into every room of the house that I want to have control of. Pi zero 2 is fifteen bucks and can run Whisper speech2text iirc, throw ChatScript on there for local command decoding and call it a day. I think I’d pay 50 to 100 per room for the convenience, paying a premium to not have my voice surveilled by Alexa just to set timers.