The Met Exhibits A best guitar pickup is actually just like a dynamic mike coil. For decades, powerful microphones have already been wired with the style coil attached with the principal of the microphone's transformer, and perhaps not introduced to surface (‘floating'). The microphone's case is normally connected to the cable shield, that is linked to the mike amplifier's ground (see Rane's site for more discussion).
By and large, dynamic microphones are very calm devices consequently of the mix of transformer isolation and balanced, suspended indication lines during, in addition to protected, humbucking coils.
So why don't you guitars? Instruments are notoriously affected by noise. Humbucking pickups are merely a partial (though essential!) solution. Well-known answer is always to move your guitar pickup to a balanced production, just like a microphone. A similar idea was printed this 2001 patent program like this The Met Exhibits?