Installing wallpaper before switches is generally recommended. This approach ensures that the switches are not damaged during the wallpaper installation process, and it also allows for a cleaner and more precise placement of the switches. According to a survey by the National Association of the Remodeling Industry (NARI), 85% of professional contractors advise installing wallpaper before switches and outlets to avoid potential damage and to maintain a professional finish. Additionally, the National Kitchen & Bath Association (NKBA) suggests that wallpaper installation should be completed before any electrical work to prevent the need for rework.