The word used is the same: INTERRUPTOR:
a device for interrupting an electric current usually automatically.

Espero que le sea de utilidad.
Saludos de OSO ¶:^)

Never seen "interruptor" in English...

I should choose "switch". This is a definition found in Diccionario deTérminos Técnicos - Collazo: término general que designa todo dispositivo destinado a cerrar o abrir uno o varios circuitos eléctricos o cambiar las coneccioens de los mismos. En casos particulares puede traducirse como contactor, llave, selector, inversor.
hay muchas opciones pero depende de como sigue el contexto , tal vez hasta se pueda utilizar el término "interrupter" (conmutador de una sola vía o dirección)

Circuit breaker may be used as well.
Interrupting device,... it doesn't sounds as the best choice, but it does the job anyway. If you have more context, you may find some other options.

Depending on the context.
GFIs can be found generally inside the house, in the kitchen or bathrooms.
Circuit breakers are normally in electric panels, and outside of the living area.

Regards.
Luis M. Luis

If it's in your house, it's a switch (NEVER interruptor) and if it's a bigger device, in a factory for example or the mains (principal supply current), then circuit breaker.

Hope it helps.