It's when the voices start telling you to do things that you should worry ;-).

Do you live near a tv tower, radio station, or in a city? That makes it more difficult to fix because the signals are very strong. Strong RF can do very strange things. I remember installing a 2 way radio in a construction vehicle and when you hit the transmit button, the winshield wipers would go on! We had to put in shielding to prevent it. Then there was the pa system in church that would pick up CB radio.