If two people own a house either as tenants in common or joint tenants and one wants to sell but the other does not the reluctant party can be forced to sell. This is called a partition action or lawsuit. While it will get the feuding parties in front of a judge, the judge would much rather the two get together and settle their differences. It is really in the best interest of the feuding parties as well. By the time they pay two sets of legal fees to go through the partition case they likely could have made more if they sold the property voluntarily. It’s much akin to getting a divorce with all the bad feelings that can arise in a case like this.
If they end up going through to the end of the case the judge will order the house sold and the proceeds will be distributed according to the ownership percentages. In a case I have currently the brother has been living in the house for five years and has never paid rent, utilities, insurance or taxes. In that case if the sister can produce receipts showing what she has paid for her dead-beat brother the judge will award the proceeds to be split evenly but the sister will recover all the expenses her brother never paid from his portion of the proceeds.
These types of cases don’t happen very often. But if you stay in this business long enough you will see everything, good and bad, when dealing with people.