[broadgage]

Terminolgy is not allways consistent in such matters.
A "3 gang" light switch is generally understood to mean 3 electrically independant switches mounted on the same faceplate. Widely used for three lights in the same room. 3 switch contacts operated by the same rocker or knob would be called a 3 pole switch (used to isolate bathroom extract fans with a neutral, fixed live, and switched live)

"Ganged potentiometers" however is generally understood to mean two potentiometers operated by the same shaft. For example to alter the volume of both channels of a stereo amplifier with a single control.
2 gang potentometers are common, more than 2 gang do exist but are rare.

Older editions of the wiring regulations DID call for a "ganged switch" to isolate the incoming electricity supply to a building. This was what we now call a 2 pole switch. Very early types were two physically seperate switches with a wooden rod that linked the operating handles.