No they don't, they use the database of license holders to find addresses of those without a license. CRT detection was stopped in the sixties and there's some

No they don't, they use the database of license holders to find addresses of those without a license. CRT detection was stopped in the sixties and there's some evidence that the "Detector Vans" were mainly tactics to scare people without licenses into getting one. https://en.wikipedia.org/wiki/TV_detector_van https://en.wikipedia.org/wiki/TV_detector_van