Mine would be creating pen and paper ciphers for my made up secret communication needs.
I repair and upgrade classic video game consoles. RGB modding NES, Adding HDMI output to a PS1 etc. Sometimes in the case of some NEC consoles like the Turbo Duo R, I’ll buy ones that are totally hopeless (capacitors in these thing leak like crazy) and pick away at it for months, I’ve had some janky looking consoles but I’ve brought them back from the dead. Always satisfying when then work again.
Do you have any pics of an RGB NES? I can’t even imagine where the lights would fit but this sounds like something right up my alley.
I should clarify, by RGB I don’t mean LED I mean modding the console to output an analog RGB signal (much better quality than the Composite of RF hookups you would normally use) for video out, you need specific hardware in order to take advantage of that higher quality signal though. Bob over on RetroRGB has a great write-up on it.