Every year, I hear people (typically heterodox or jokers) talking about "Chanukah bushes" (likely a parallel to Christmas trees). Now, beyond the obvious of this not being a traditional practice, would such a thing be chukkat hagoyim, or otherwise forbidden?
The Chochmas Adam 89:1 wrote that the Vilna Gaon abolished the minhag of decorating the synagogue with trees in honor of Shavuos because of the problem of Chukkas HaGoy (i.e. the practice of decorating a tree for the Christian's Holiday). The Chochmas Adam held that such a problem would even justify nullifying a practice mentioned (but not commanded) in the Torah. Certainly it would seem forbidden because of Chukkas HaGoy to establish such a practice in imitation of their custom.