Black Sabbath Book A electric guitar pickup is essentially just like a vibrant mike coil. For decades, vibrant microphones have been wired with the voice coil attached to the primary of the microphone's transformer, and perhaps not introduced to ground (‘floating'). The microphone's situation is usually linked to the wire shield, which is connected to the microphone amplifier's ground (see Rane's website for more discussion).
By and big, energetic microphones are very calm devices as a result of the combination of transformer isolation and healthy, flying indication lines through the duration of, along with shielded, humbucking coils.
So why not guitars? Instruments are notoriously affected by noise. Humbucking pickups are just an incomplete (though crucial!) solution. Well-known answer is to move practicing the guitar collection to a healthy productivity, being a microphone. A similar thought was published this 2001 patent application such as Black Sabbath Book?