on/off switch vs on-off switch

on/off switch and on-off switch both are nouns.

Word	Noun	Adjective	Verb	Adverb
on/off switch	Yes	No	No	No
on-off switch	Yes	No	No	No

As nouns, on/off switch and on-off switch are synonyms defined as:

on/off switch and on-off switch: a hinged switch that can assume either of two positions

Other synonyms of on/off switch include toggle, toggle switch.

on/off switch (noun)	on-off switch (noun)
a hinged switch that can assume either of two positions	a hinged switch that can assume either of two positions