Identification of common RFI/EMI sources?
This is an interesting topic, and in fact was the main subject of the DARPA SDR Hackfest in Brussels January/February this year. https://fosdem.org/2017/schedule/event/darpa_hackfest/ (huh, I'm even on that video – at least the back of my head is)

So, no, to my knowledge, there's not such a database by now, and you'd have to build up experience yourself, though chances are that a few sources are easy to spot – supplies will have spectra of square waves, USB devices have an 11MHz oscillator, 1GigE runs at 125 Mbd (but I don't believe it's going to be very prominent – these cables are usually well-designed :) ), and you can test a light bulb SMPS hypothesis by turning of lights.