we actually only encounter salt as a solid most of the time. when salt dissolves in water, it is part of the liquid, but it's not liquid salt exactly - that would be molten salt, and i think it requires much higher temperatures than we see on earth.

the gas phase nacl we detected in orion is just gas, not plasma - the nacl is not ionized. when we see nacl, it is as a gas, but we think that most nacl in space is solid. it's integrated into the dust particles that pervade space, and on those particles, it is solid.

we do detect na and cl on their own in elemental form in gas too. when there's enough ultraviolet radiation around, the nacl gets dissociated (split) into its constituent atoms. we see this in the diffuse interstellar medium, ie, not close to any particular stars