The wife of your uncle, according to you, is the sole owner of the home (the sole person on the title to the property). That means the home is hers to do with as she likes. Unless your grandparents have a long term lease with the owner the owner can give them the proper notice to get out under the applicable state law and once the time period of that notice is gone the owner may start eviction proceedings if they have not moved out.

Why in the world did the other family members contribute to pay for a home that they have no ownership interest in, especially a home owned by the wife of their brother, if they wanted some say in what happened with the house? That was foolish indeed. I’m going to guess that they didn’t any written agreement with their sister-in-law about the use of the home in exchange for that cash either, right? If that’s correct, all the cards are held by the sister-in-law and your uncles are left with really no recourse for the cash they chipped in for this. There are lots of better ways they could have done this. They could have had the home owned by a family partnership in which every sibling that contributed the cash would be a partner and thus all would have a say in what happened to the home, for example. There, the partnership agreement would spell out exactly what the arrangement was and how decisions would be made. Or they could have created a trust to own the home. Or even set up the home ownership with your grandparents having a life estate with the sister-in-law as the remainderman if they wanted to have her get it after the grandparents died. Your husband and the other brothers that don’t want to kick out the grandparents might want to consult a real estate attorney in the state where the property is located to look over the deed and any other documents that relate to this property and see if there is anything they can do to keep their parents in the house. But just from what you have said, it doesn’t look good.