Single-Pole Switch
The Spruce / Claire Cohen
A single-pole switch is the general-purpose workhorse of switches. You'll know if your switch is single-pole because it will usually have ON/OFF symbols embossed on the face of switch (though the ON/OFF markings might be omitted on rocker-style switches).
Examined closely, you'll notice that a new single-pole switch has two brass-colored screw terminals attached to the body of the switch, plus a green screw that is connected to the metal strap. In normal use, this type of switch is used to control the flow of current through "hot" wires in the circuit (usually black wires).
With single-pole switch wiring, each of the brass-colored screw terminals is attached to a hot wire, and there is generally no neutral wire connection at all. The circuit's grounding wire (usually a bare copper wire) is attached to the green grounding screw on the switch.
As a general rule, neutral (usually white) wires are not connected to switches. If two neutrals are present in the box, these wires typically are joined so that they continue through the box without touching the switch. Or you might see a single neutral wire passing through the box. Sometimes, however, you might see a white wire attached to the switch, and this is when it is functioning as a hot wire. In this case, the white wire should have a wrap of black tape on it near the switch terminal to indicate that the wire is operating as a hot wire and not a neutral wire.
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