Hello there! My theremini picks up radio waves. Usually the sound is simply a little disturbed, but when I press my ear to the speaker, I can hear people talk and sing. And no, this does not happen to me on a regular basis or away from the theremin, too. 
Any ideas what can be done about it?
These voices came from the other space? 
Hi Flicki,
all you can do is: in the Advanced Menu set the Response Mode to mid or low if it’s set to high.
It’s very sensitive to pick up radio signals and other electronic radiations, coming from wall-warts, motors, neonlights, wifi, cellphones and of course also radio-stations.