There was a television programme in Finland years ago, where they showed one of those "detectors" being used inside a building to find unlicensed televisions. W

There was a television programme in Finland years ago, where they showed one of those "detectors" being used inside a building to find unlicensed televisions. What was visible of the device looked like an oven thermometer. It was the subject of much fun-poking, and there were screenshots floating around, but I can't find any of them now.