To be honest I have never heard of such a thing happening. I suppose anything is possible. Considering that radio waves simply bounce around in the atmosphere until they hit a receiver, it could happen as you described. The true test would be to unplug the speakers, make certain they are turned off, unplug them from the computer and then see if you still hear the radio signals. If you do, well then you have something else going on. Now that something else does not necessarily mean you have a ghost or anything like that - the construction of your home could be a factor as well. Sometimes homes are constructed with materials that are very good receivers of radio frequencies. So it could easily be something like that. If your home is constructed of wood, then perhaps the signals you are getting are the result of electronic impulse impressions that are believed to become part of a location. Beyond that, I don't really know what to tell you until you test things out by unplugging the speakers and seeing if the signals are still there.