Someone took apart a rotary phone, removed the call-making guts of it, and replaced them with a Google Home Mini. The best part about this mess of circuitry? The receiver acts as the smart speaker's output. Yes.
A person by the screenname of Movieman_75 mostly posts memes in Gen Z-type subreddits, but he has shown off his creative side with a Minecraft replica of Cincinnati's Union Station train terminal and has asked for help with the keys on an IBM Selectric typewriter he bought on eBay.
It was just yesterday, though, that he posted a 40-second video showing off his speaker-into-a-speaker hack using what may be a Cortelco Model 500 as the host unit.
All of this could be improved, though. Movieman explains in the comments that the far-field microphones are still being used in this hack — he placed the Mini upside down to increase their viability — as opposed to the one on the phone's receiver as he couldn't figure out the wiring paths for those. He also said that the receiver's speaker wasn't designed to take the volume of such a modern, hi-fi source, so any output generally pushes heavy on the bass.
Maybe this is a DIY in progress, though some would rather ask "DI-why?" We've reached out to the original poster for some comment and will update this story if we hear back.
For now, though, not a bad job, kid.