go to an electrical store like haymans or L and H and ask for an arcatrave switch plate, they look similar to those, you may find em in bunnings too in the 240v switch section. you may want the standard version that just has 2 screw holes that you cover with the little round screw hole covers as the other ones there is a face plate that clips onto a base plate and the face plate might pop off here and there depending how full the switch hole is with the cables you will run through them.
