Such information may be filed by the Attorney General or by the county attorney of the proper county whenever either of such officers deems it his duty so to do, except that the county attorney shall not have authority to file such information against any state officer or a judge of the district court; Provided, however, that any elector of the proper county may file such information against any person unlawfully holding or exercising the functions of any public office in the state, other than state officers or judges of the district court, whenever the county attorney of the proper county shall refuse so to do within ten days after he shall have been notified in writing by any elector that any such person is disqualified by the Constitution or the laws of the State of Nebraska to hold the office in question or to exercise the functions thereof. Any person other than the county attorney who shall institute such action shall file with such information in the office of the clerk of the district court a bond signed by a duly authorized surety company or by two resident freeholders of the county in which the action is filed, the amount of which bond shall be not less than five hundred dollars and be fixed by, and the sufficiency of the sureties thereon approved by the clerk. The bond shall be conditioned that the plaintiff shall prosecute the action without delay and that he shall pay the costs of such suit including a reasonable attorney fee to the person against whom such information is filed should the action be unsuccessful. The amount of such attorney fee shall be fixed by the court and taxed as costs in the action.