The proceeds of any municipal bond sale, which have not been used for the purpose issued within three years after date of issue, may be disposed of by the governing body of the municipality as follows:

1. Sufficient funds must be transferred to the sinking fund of the issue in an amount equal to the principal of bonds outstanding and the interest requirements.

2. The governing body may, by a two-thirds vote of all its members, transfer the funds to any or all other debt sinking funds of the municipality.

3. The governing body, upon approval by a majority vote of the qualified electors, voting on the question at an election called therefor, may use the funds for some other purpose authorized by law.

If any funds remain, they must be transferred to the general fund of the municipality.