(1)  If the Commission intends to intervene in a proceeding, the Commission must file a notice of intervention in accordance with Form 5.

(2)  Not later than 3 days before the date fixed for the hearing at which the Commission intends to appear in the proceeding, the Commission must serve a copy of the notice, and any affidavit on which it intends to rely, on the plaintiff and on any other party to the proceeding.