Television interference.

Much of what appears to be interference may be due to weather conditions, faulty antenna or poor connections. Indoor TV antennas are also prone to problems, as will be any system where the reception is poor to begin with.
Check these first, and make sure that you have a strong signal.
If you have a good signal, and are certain it is a local CB interfering, you can connect a low-pass filter in your TV coax. The best ones are the braid-breaker type.