MYTH: Humbucking pickups have two coils which are "out-of-phase."
REALITY: That statement is at best misleading, at worst, incorrect. See the section on pickup theory for a complete treatment of this subject. In short, the two coils of a humbucker have opposite electrical and magnetic polarity so that, while the noise signal is out of phase, the primary signal is in-phase.

MYTH: "TBX tone control" means that the middle pickup is of opposite polarity from the neck and bridge.
REALITY: "TBX tone control" has nothing to do with the polarity of the pickups. All modern Fender Stratocasters (since the mid-'80s) have a middle pickup with reverse polarity. Except, of course, for accurate vintage reissues. It's a pretty good bet that Strat-type guitars from other manufacturers also have the reverse-polarity middle pickup. "TBX" has to do with the way the tone controls work.

MYTH: If you have an earlier Strat, you should reverse the leads of the middle pickup.
REALITY: Doing so will give you a very weak and sickly sound at "2" and "4." Early Strats were shipped with all pickups having the same polarity. Reversing the leads on the middle pickup will reduce noise at the "mixed" positions. However, the signal will also be canceling and you'll end up with a thin, weak tone in those positions.

MYTH: My guitar has a mid-range (or bass, or treble) boost.
REALITY: Maybe, but only if your guitar needs a battery or takes power from some other source. It is impossible to "boost" a signal or any part of it in an unpowered circuit. What you actually have is a tone cut. The stock tone control on your guitar, for example, works by throwing away (shunting to ground) high frequencies as you turn the tone control "down."

MYTH: Single-coils just naturally hum and you can't do anything about it.
REALITY: The above statement is very misleading. Single-coil pickups are more susceptible to hum, but proper shielding and wiring can reduce the hum to barely noticeable levels in most cases.