if there is a separate one, it's not anywhere accessible. we live in a ground floor flat with no loft.
thanks for your thoughts everybody, i'll have a look in the ceiling rose tomorrow and see where that takes me.
apologies, i've had a rummage through a lot of the older extractor fan posts but couldn't find what i was after (possibly because i was blinded by jargon more than once)
my old extractor fan died so i decided to replace it. it switched on with the light switch and stayed on for a while after...