Not sure why you want to plug in the fan? Since you are switching, you can wire direct to the fan wires (cut off the plug). Either way should only need one 2-wire cable to/from the fan and switch.

Well eventually (just a couple of days ago) as suggested by Steve, I did wire the extractor fan directly to a wall switch next to the light switch using a lighting circuit. I opened up the fan and connected the wires directly inside the fan using wire nuts (because there were no screw-kind of terminals inside). I just used two wires (live and neutral) because there were only 2 wires originally coming out of the fan with a 2-pin plug on the end. It's working fine.

So my next question is should I run an earth cable from the switch to the fan and if yes, then where would I attach the earth cable to the fan? Note that the fan is about 3 metres up the wall and it's casing is all plastic. I'm wondering if the earth cable is supposed to "protect" the cables going to an appliance and not just the appliance itself?

Thanks.

JB.

No need to earth the plastic fan, it only had two wires originally (double insulated) and it's well out of reach anyway.

By the way, for those asking why use a plug and socket? It's easier to replace or remove the fan for repair.

Switchable wall sockets are very common in US home wiring installations. Many rooms do not have overhead light fixtures and rely on being able to plug in a light fixture into the outlet and allow it to be turned on and off from the wall switch at the entrance to the room. Makes it easy to decorate the room without an unsightly overhead fixture,

Their construction is such that it is easy to isolate one socket from the other on the dual socket fixture by removing, breaking off a link on the live side. In addition the sockets are mounted on metal plates that are also internally connected to th earth connection and when you use metal face plates the screw holding on the faceplate earths the plate. daisy chaining the sockets in each box is not required.