What is your definition of interference? Is it a pulsing noise? Is it a constant hash noise? Is it a constantly scratchy noise that comes in and out every few seconds for a short period of time? None of the above? Is it in the house only? Or is it all over town? Do you have a handheld, base, or mobile station? What radio is it, and what antenna are you using?
Each one of the above questions will have a very different answer, so you will need to be very specific with your question.