The Southern China Morning Post may or may not be a completely unbiased source in the matter.

Asking the real questions.

I’ve seen this one which may fit what you’re looking for. No idea about open source firmware though.

This one might work for you too.

Really though, if you’re already spending money on a smart switch, you should probably just replace the outlet, other switch, and faceplate with decora (rectangle style) versions while you’re at it. It’s only going to run about $10 total for all those. Plus you can then use a smart switch that meets your firmware needs.

I just printed this out as well! So much better than the button. Though having a grey lever in a white fridge isn’t doing it for me. That’s a good enough excuse to go buy some new filament!

I do think it would be better to print it on the opposite side than what he shows in his screenshots. That way the rougher side where the support material attaches will be facing the inside of the fridge.

If I understand it correctly, annihilation is a 100% efficient process that converts all the matter into energy. After the process is complete there is no matter left over and only energy in the form of light, heat, and other energy forms that go way over my head remains.