Yes, it has happened to me, 11 years ago. It turned out to be short-wave or CB Burn Through on my unshielded speaker wire. I braided four, 22 gauge wires around my speaker cable which acted as shielding. A few months later I switched to Kimber 4TC, which is braided. The braiding provides shielding. I still use the Kimber along with 12 gauge copper solid core irrigation wire twisted in a double run configuration.
As we say here in Vegas, Good Luck!
As we say here in Vegas, Good Luck!