The #1 generator of wideband HF RFI that I have found around my house are "smart" 12v battery chargers/tenders. Specifically the NOCO Genius brand. I have a couple of these and they destroy HF with ridiculous RFI. Therefore I only use them occasionally to touch up a battery, I never leave them on a battery all of the time.
The 2nd worst generator of local RFI is undercabinet 12vdc LED strip lighting. The tiny switching power supplies they use are complete garbage.