Answered by Shaykh Ilyas Patel
Are women allowed to have hair or synthetic hair attached to the normal hair?
Assalamu alaikum,
The Prophet (Allah bless him and give him peace) said, “Allah curses women who wear false hair or arrange it for others…” [Bukhari]
The early 20th Century CE Damascene Hanafi scholar, Allama Nahlawi (Allah have mercy on him) mentions in Durar-al-Mubaha, a work on the fiqh of the lawful and prohibited and proper manners:
‘Who wear false hair’ means women who wear hair from others or who wear other women’s’ hair falsely. And ‘arrange it for others’ means those who request others to attach the hair.
Indeed, there is dispensation in using hair of other than a human. It is mentioned [by the 6th Century AH Hanafi imam, Qadikhan, whose work is a major reference for the fatwa positions of the Hanafi school] in al-Khaniya that, “There is no problem if a woman puts fur of camel and goat into her roots of hair and strands.” [Allama Nahlawi, al-Durar-al-Mubaha, 266]
Source: http://www.SunniPath.com