What is the ruling on a woman wearing a wig to adorn herself for her husband?

Spouses should beautify themselves for each other in ways that strengthen their relationship and are within the bounds of Islamic law. Wearing a wig, however, involves imitating disbelievers, and the Prophet (peace be upon him) forbade this, saying: "Whoever imitates a people is one of them." It is also akin to hair extensions, which are forbidden, as the Prophet (peace be upon him) cursed the woman who adds hair extensions and the woman who asks for them to be added.