A BIG THANKS TO EVERYONE! I found the problem purely by accident. I have a intercom setup between the house & barn... I happened to go to the barn and heard something... it was the house end of the intercom, accidentally set to "monitor" position!!!! I blame the wife, she blames me... but that was the problem. They must occupy the same setup on the wiring. Once again, thanks for the suggestions. They are all safely tucked away for future use... Jack