What should a wife do if her husband built a house with usurious money from the bank, despite her objection and knowledge of the prohibition of usury, and she fears that sin will befall her from living in it?

The husband erred by falling into usury, which Allah Almighty has forbidden. However, the sin of usury is connected to his personal accountability, not to the specific money itself. It is not forbidden for the wife to live in and benefit from the house. She is absolved from the sin of her oath by offering expiation for it, and there is no blame upon her for that. The husband must repent to Allah for the sin of borrowing with usury.