One of the meeting rooms here at work has a couple of big panels for displaying presentations, and they're regularly misinterpreting noise on some line or other and changing their brightness/contrast/etc settings. It's highly annoying. I imagine there's some kind of data line plugged into the TVs which is picking up interference and causing them to freak out.
I inherited an old Sharp LCD TV that has a serial port. I did some digging and discovered I can power it on and off thru the serial port (amongst other commands). It serves a role in my home where it needs to be on part of the day. Turning it on and off via serial is very, very nice.
Using a whole Raspberry Pi seems like overkill, though: Support for a wide variety of common USB serial chips is already built into esphome. https://esphome.io/components/usb_uart/
Just wire it up with a cheap dev board, build a firmware image for it, and that end of things is... done, right?