When the jurors summoned have not been selected by jury commissioners or by drawing the names from a jury wheel, any party to a suit which is to be tried by a jury may, before the jury is drawn challenge the array upon the ground that the sheriff or clerk summoning the jury has acted corruptly, and has wilfully summoned jurors known to be prejudiced against the party challenging or biased in favor of the adverse party. All such challenges must be in writing setting forth distinctly the grounds of such challenge and supported by the affidavit of the party or some other credible person. When such challenge is made, the court shall hear evidence and decide without delay whether or not the challenge shall be sustained.