John,
I believe the SS-Funkschutz was mostly concerned with "Funker" or wireless duties. The Ordnungspolizei also had radio finder units to track down clandestine wireless transmissions. The difference would be funken duties involve radio and wireless telegraph transmissions rather than hard wire land lines that were the baliwick of the Postschutz.
There were a lot of Governmental law enforcement organs keeping track of the public!
George
