Small ticking noise behind Dash on ST170 Ford Focus?

On my ST170 (03 plate), there seems to be a small ticking noise coming from behind the dashboard, around the center column area, i can only hear it when I rev the car, or when I switch the engine off. When i switch the engine off you can hear the ticking noise slowing down (quickly) and stopping.

Have not got a clue what it is, Hope i've explained it well enough.

Anyone else experienced similar problems?

Any Help??!!