The Eighteenth Century Center is featured in Pop Pixie located in Pixieville. It is a treatment center managed by Rex and Maxine (disguised as Pixies with outfits from the eighteenth century).
Their plan was to ruin the hair of other civilians so Pam gets the blame of it. When her treatment center was closed by Ninfea, the victims of the two Elves had to pay at their center for a 18th century wig and make-up.
But when their plan was stopped, they get punished by Ninfea. They must work for free at Pam's treatment center.