the.com/wig

means An artificial covering of hair worn on the head, or slang for an uncontained, over-the-top reaction of shock or excitement.

from The word is a shortened form of 'periwig,' which English borrowed from French 'perruque' (itself tracing to Italian 'perrucca'), meaning a head of false hair. The slang sense — 'to wig out,' meaning to lose composure or flip with excitement — emerged in the 20th century, likely from the image of one's wig flying off in a fit of shock or ecstasy, hair and hysteria both coming loose at once.