If such debt remains unpaid for three months or more, the party rendering such service may sell such article at private or public sale and the proceeds, after first paying the expenses of the sale shall be applied on the payment of the debt, the balance, if any to be held for the debtor. If the debtor's residence is known, notice in writing must be given the debtor of the amount due and the time and place of the sale before said sale, said notice to be mailed to his street address. If debtor's address is unknown, notice may be given by posting it in the county courthouse of the city or town where the service is rendered or the courthouse nearest thereto, for two weeks before said sale, said notice setting out the time and place said sale will be made and the article or articles to be sold and the name of the debtor or debtors. Such notice may also be published in a newspaper published in the county in which such sale is to be had and when so published for two consecutive weeks shall be sufficient notice of said sale whether said notice is also posted at said courthouse or not.