Switch says common wire. Is that white or black wire?

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    With all the thrash on this question the true answer is it depends on the application. A 3 way switch has a black screw for the hot this is common to the travelers so in this case black is common. For the majority of wiring we consider the neutral white or gray wire common. – Ed Beal Nov 14 '18 at 17:03

Black (hot) wire, brass screw (small blade)

White (neutral) wire, silver screw (wide blade).

Ground (bare or green) wire, green screw. (U blade)

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    As a memory aide: BLACK POWER! – Steve Wellens Feb 29 '16 at 16:26
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    Black to the brass to save your ass – Joe Phillips Feb 19 '17 at 1:15
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    In electronics, black is ground and white can be hot so I used to say it's "white hot". After years of electronic design, I still have to remind myself when I work on house wiring. – Rob Oct 15 '17 at 9:56
  • For the commonest case, I just remember that between the white and black wires, the lighter colored wire (white) goes to the lighter colored terminal (silver). – simpleuser Apr 5 '19 at 20:35

The ACTUAL question asked was: "which color goes to COMMON?" Answer: WHITE.

The only upvoted answer so far does not clarify anything about COMMON. This does not answer the question asked.

Only downvoted questions attempted to answer which color is COMMON, but are ambiguous: e.g., "white = common, neutral, or ground." Green is ground; this is not the same as common!.

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    Hello. I'm fairly sure I edited this same question a couple of days ago, removing the concluding insult. I don't see the answer now; I'm guessing it ended up being deleted. Please, if I'm right, don't add multiple accounts, hoping to get one of your answers accepted. – Daniel Griscom Nov 12 '18 at 0:02

White. The "common" is the "neutral" or "ground" wire, depending on the type of circuit. In normal US residential wiring, you'll have a black "hot" wire, a white "neutral" or "common" wire, and a green or bare "ground" wire.

Occasionally you may encounter a blue hot wire in ceiling fans or a blue or red traveler wire between 3-way switches.

Reference.Com: https://www.reference.com/science/common-wire-electrical-circuit-e77a01c6513ed708

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    Neutral is not the same thing as ground. – Rob Oct 15 '17 at 9:55
  • The "neutral" wire is connected to a bar in the breaker box that is connected to ground. It goes to ground. – Karl Wilbur Oct 15 '17 at 13:01
  • "In the electrical trade, the conductor of a 2-wire circuit connected to the supply neutral point and earth ground is referred to as the "neutral". ... All neutral wires of the same earthed (grounded) electrical system should have the same electrical potential, because they are all connected through the system ground." – Karl Wilbur Oct 15 '17 at 13:09
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    Generally, neutral is connected to ground at the circuit panel but that's not what I'm talking about. You said "common" is the same thing as neutral or ground and they are not! If they were, why do you need both? Why do some older homes not even have a ground wire? In reality, the neutral wire is the return wire back to a power station but a ground wire is not! It's more complicated than that simple statement but far more truthful than your answer or response. I did not read through this reference – Rob Oct 15 '17 at 15:43

You have a 3 way switch if it says common(common is the wire going from one switch to another) didn't know outlets had 3 way? But I only know the basics

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    Going from one 3 way switch to another are two "travelers", not a single "common". – BMitch Mar 14 '16 at 21:53

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