Once again, contact with moisture is the culprit here, though water-resistant varieties of wallpaper are less likely to become wet and develop mold. Using a high-quality exhaust fan or dehumidifier and leaving the doors or windows cracked after bathing will keep this issue at bay. 

Yes, many installation and painting services include wall preparation, such as patching holes, smoothing surfaces, sanding, and priming. It is recommended to confirm the specific preparations included with your provider.

You should be aware of the current wallpaper and interior trends before hanging it, especially if you are planning on selling or listing your home soon. Do people in your market tend to prefer bold designs and accent walls, or does having a simpler print all over seem like a better idea? Lastly, you want something that appeals to your aesthetic preferences; hanging wallpaper is an investment of your time and money after all.

If you need a stronger magnetic surface, or you need to use a different type of paint in the room (like waterproof paint in a damp basement), there are other accessible options. You could fit a steel panel over the wall, try magnetic wallpaper, or apply chalk paint instead. 

If you want an inexpensive shortcut, hang a pinboard or chalkboard on your wall. These removable options are ideal if you’re a renter who can’t repaint or plan to move in the near future.