We have a Sputnik chandelier above our dining table in my home. Recently, we found a rotary wall phone and decided to convert it into a controller for the chandelier.
The conversion involved removing some of the internal electronics in the phone and replacing them with a WiFi-enabled Arduino. The microcontroller sends a request to a Philips Hue hub in the home, which controls the chandelier through an in-wall Hue-compatible dimmer switch.
Though I built this as a personal project for home, it’s useful as a teaching example too. The technical details of the system are available on my gitHub light projects site.
A video of the phone and chandelier in action is available at this link.