#145 Hair Covering for Married Women
A married woman is halachically forbidden to expose any of her hair in public, by virtue of das Moshe, Torah law. This applies even to a tiny bit of hair, much, much less than a tefach, handbreadth. The so-called halachic loophole of exposing less than a tefach of hair has no basis in halachah. Even in the privacy of her own home a woman's hair should always be covered, as per the laws of modesty, just as covered parts of the body are to remain covered even in private. According to the Zohar, the requirement for a married woman to cover all her hair at home is almost as severe as the Torah law of covering all her hair in public. Women throughout the ages have accepted the Zohar's opinion as normative and binding. The merit for scrupulously observing this mitzvah is described in the beautiful story of Kimchis, who thereby merited seven sons who became kohanim gedolim. A sheitel, a wig covering made of hair, even real hair, is perfectly fine, even if it looks like a woman’s own hair, or is even more beautiful. Although there are some poskim who forbid wearing a sheitel, the common consensus is that a sheitel is absolutely acceptable. There is no issue of wearing a sheitel unless there is a minhag, custom, in a particular place not to wear one, which is very rare nowadays. It is certainly preferable to wear a wig rather than to wear another head covering, which may sometimes allow some hair to show. Obviously, in all cases a sheitel should be worn in the most tzniusdik, modest, fashion. Wigs, as all garments and accessories, need to be refined and not draw attention to oneself.
P.S. It should be pointed out that the Lubavitcher Rebbe highly encouraged the wearing of a sheitel rather than any other type of hair covering. The Rebbe also quoted many times the abundance of material and spiritual brochos the Zohar mentions that will be granted to a woman who is careful in observing this mitzvah, as well as to her husband and children.