How does a wire - the kind rats wear - look, and how does it work exactly?
Also, isn't wearing one risky? Not only the 'getting caught' factor, but isn't it easy to slip off the guy, and expose him or be revealed? At least on the Sopranos, a wire seemed to be taped to the guy's chest, and it looked like a microcassette recorder with a microphone attached. Is that how it tends to look? How wouldn't it be detected when say, hugging the guy?
