חלק יו"ד - ג'נג
בברכה - המחכה לבשו"ט
שייטל: ראה לעיל אגרת ב'תתקע, ובהנסמן בהערות שם
From Kissui HaRosh -- Properly Covering the Hair With a Sheitel / Translated By Rabbi Sholom B. Wineberg (www.sichosinenglish.org/books/kissui-harosh/05.htm)
Regarding the engagement of ..., surely you and your wife will exert your influence on ... that she establish her home upon the foundations of Torah and mitzvos, as they are illumined by the luminary of Torah -- Toras HaChassidus.
Among the matters that are to be assured prior to the marriage is the kallah’s agreement to wear a sheitel. I am quite sure that the chassan will not only not hinder her wearing a sheitel, but on the contrary, will assist in this matter and be satisfied that she does so.
The necessity of a sheitel surely is not in need of explanation, particularly as we readily observe that young women who fulfill their obligation of kissui harosh with a scarf or kerchief, do so for only a short period of time.
This is in addition to the fact that even during this brief period of time, they commonly breach and violate this matter.
(Igros Kodesh, Vol. X, p. 92)