It is a system for a church,a amp, mixer board,and speakers. A radio station in next door,the radio broadcast is coming through the speakers. Would a insulated speaker wire elimate the sound,and what gauge.
Just a suggestion, but I would discuss the issue with the radio station. Surely they have an engineer on staff that could help.
I think though, that some sort of isolator would be a better option than different awg wire. You would need to find out what frequency they are broadcasting at and get isolators that kill that range. Insulated wire might help, but probably not completely.