may be inserted into a switch hole not shown in the direction of front and rear of the cabinet on the front panel 8 and may be disposed at the front of the front panel 8 the coupler 26 may cover the switch hole the connectors 28 may be formed as ribs that protrude from the switch housing unit 24 toward the coupler 26 the connectors 28 may be evenly spaced apart from one another and thus a space s may be provided between the connectors 28 the spaces s may serve to prevent water from accumulating between the front panel 8 and the switch housing unit 24 by permitting water to flow there between a mounting bracket 34 is installed on the front panel 8 and is coupled to the switch housing unit 24 the mounting bracket 34 has a hole in the middle the hole of the mounting bracket 34 corresponds to the switch hole first and second engaging protrusions 34 a and 34 b are formed on either side of the hole of the mounting bracket 34 the mounting bracket 34 and the switch housing unit 24 may be hook coupled to each other by using a hook 30 and an.