Is a wife taking her husband's money without his knowledge and spending it on their home considered theft?

A woman taking from her husband's money falls into two categories: either with a permissible (shar'i) or customary (urfi) permission, or without having the right to do so. In the case of no permission, what the wife takes is considered an act of transgression and theft, for which she is sinful and liable, but the hadd punishment is not carried out on her due to the شبهة الاختلاط (doubt arising from close association/intermingling).