10 ILCS 5/19-11

Whenever it shall be made to appear by due proof to the judges of election that any elector who has marked and forwarded his ballot as provided in this article has died prior to the opening of the polls on the date of the election, then the ballot of such deceased voter shall be returned by the judges of election in the same manner as provided for rejected ballots above; but the casting of the ballot of a deceased voter shall not invalidate the election.