Thanks for the reply! You are not wrong, however this is just the basic idea.
My plan would be to expand on this, to have the arduino become a controller for all the electronics in the room. I got the idea from a hotel where they have a similar system in place.
One issue I thought of is that the power for the light is 240V and the arduino uses 3-5V. I'm guessing I would need some sort of electronic switch and a transformer in between? If that's correct wouldn't it create a lot of heat?
Adam