Is it permissible for a husband to house a strange man in his home without his wife's consent, and is her approval necessary in this matter, and what are the rulings related to that?

A husband must provide a private and independent dwelling for his wife. He is not permitted to compel her to live with any of his family members or relatives if she refuses, as this would harm her and violate her right to a private dwelling.

Regarding hosting a non-mahram (definition) man: 1. If his stay is temporary (hospitality): The husband may host the guest as long as a private and secure place for her privacy is available to the wife, provided a mahram or the husband is with her, and there are multiple rooms or the space is large enough so that the non-mahram does not see her. The permissibility of this is indicated by the hadith (definition): "A bed for a man, a bed for his wife, and a third for the guest." The wife does not have the right to object unless she incurs direct harm. 2. If his stay is permanent or long-term: The wife has the right to object, and the husband is not permitted to compel her; because the presence of a non-mahram contradicts her right to an independent dwelling.

Additional rulings: Seclusion (khalwah) between the guest and the wife must be avoided, and lowering the gaze and adhering to Islamic manners are obligatory. A woman serving her husband's guests: Some scholars believe that it is not obligatory upon her. The preponderant view is that she is obligated to serve her husband's guests according to what is customary, unless it causes her severe hardship.