For what it's worth, I agree with our lemony friend. Your TV is picking up stray signals.
It could be that someone occasionally aims a radar-guided missile at your TV, then changes his mind prior to launching it.
At the very least, you should install an ECM pod on your roof, and have bags of reflective, metallic chaff handy in case it is launched. If the missile is launched, quickly throw the chaff into the air. It may confuse the missile and cause it to veer a few inches off course, thereby sparing your TV. This may be hard on other furniture, however.
If you have a couple of extra bucks, you might look into buying a Phalanx close-in missile defense system.
