I have a bathroom fan, but it only runs when the light is on (i.e. no delay). The fan itself is really good, but it should really run on after (I think this might be part of the Building Regulations here in UK).
I don't want to replace the fan, so was wondering if you can just get the timer unit to attach in-line somewhere.
I've checked and the wiring is there for the permanent live as well as switched live, so am kind of hoping it will be simple!