Sources for mindcontrol
As moonstruck uses ELF, there are some possible sources that I have not seen mentioned.
The World Hum is one(e.g. Taos hum, Auckland hum, and what my neighbors and I hear in SoCal). Using a spectrum analyzer I see it varies in frequency (have seen 54 Hz and 57 Hz) and has a very low amplitude but is audible.
Certainly that could be a carrier frequency.
Curious as various brain waves use frequencies below 20Hz. E.g. Beta, Theta, Delta, Alpha….