Welcome to the family the TP-Link HS220. A wifi-enabled dimmer switch. You know you can always use another WiFi switch product!
For once in the history of smart switches we have a neutral wire (the white), normally the experience is to open the existing wall plate and curse the electrician who, sometime during the ascendency of disco, saved $0.02 and skipped the traveller.
Installed. IP assigned. Discovered in Home Assistant. Working. Great!
One minor hiccup. I bought this since it would work locally (I don't want some new cloud service they'll bring in a few months). And, it does. The Kasa app does allow you to login as a guest and setup new devices without creating an account. Except for the HS220. The other switches work. Huh? Well, dummy account created, device assigned to the IOT network (which has no Internet access), and it works from Home Assistant, So, minor speedbump, the device does work without Internet.