The capital outlay fund shall remain inviolate for the making of any capital outlays and the money shall not be disbursed from the fund except for such a purpose unless the district board submits a proposition to the electors of the district to obtain their consent to use the money in the fund for some other specific purpose. The proposition may be submitted at any election. A two-thirds vote of all the voters voting at the election is necessary to authorize the expenditure of the money for such other purpose.