can i glue wallpaper to a high gloss paint?
do I have to sand high gloss paint before I paint over it or can I just prime it?
You can PASTE wall paper to almost anything. As to it's sticking or not depends on proper prep work. Gloss paint will most certainly need to be sanded( lightly) and ANY surface will need to have a wall covering primer applied for proper adhesion and perhaps more importantly removal down the road.