There seems to be many different AM FM Tuner Modules that have been used with all of the NuTone NM100 and NM200 Radio intercom Master Stations
I spoke with someone that has much more first hand experience with the M&S Systems DMC Series and he said that there has been many problems with the AM FM Tuners in the DMC Series, which means that those problems would be the same in the NuTone NM Series
This AM FM Tuner Module is fairly typical of what you would find in an inexpensive "radio" now-a-days.
The different sections of the tuner are "walled off" to prevent interference between the sections.
When the module is fully assembled, there are metal covers over the top and bottom of the boards, to shield it against interference
This Tuner Module would be the same as used in the M&S Systems DMC Series of Intercoms