The county election commissioners shall place the name of any person eligible to hold the office of trustee on the ballot used in the election, provided that such candidate shall have filed with the county registrar, not more than one hundred five (105) days and by 5:00 p.m. not less than seventy-five (75) days prior to the date of such election, a petition of nomination signed by not less than fifty (50) qualified electors of the school district. If the seventy-fifth day before the election falls on a Saturday, Sunday or legal holiday, the petition required under this section shall be filed by 5:00 p.m. on the business day immediately following the Saturday, Sunday or legal holiday. Where there are less than one hundred (100) qualified electors in said district, it shall only be required that said petition of nomination be signed by at least twenty percent (20%) of the qualified electors of such school district. If such person be a candidate for an unexpired term, he or she shall indicate the term for which he or she is a candidate in such petition; otherwise he or she shall be deemed to be a candidate for a full term.
If after the time for candidates to file the petition of nomination provided for herein there should be only one (1) person to qualify for the office of trustee, then no election or notice of election shall be necessary and such person shall, if otherwise qualified, be declared elected without opposition.