Do old fashioned neon bulbs produce RFI? My Google-Fu is failing me, you get 10,001 hits on CFLs, modern LED bulbs, computer case neon bulbs with noisy little inverters, and so on. I am thinking more of the little NE-2s and bigger NE-42s that have no power supply at all. How about neon signs like a bar sign with a high voltage transformer? I have to think those would make RFI, but I have not tested one.