Remove the molding around the door by sliding a screwdriver between the molding and the wall and prying them apart. Tap the end of the screwdriver with a hammer to ease the screwdriver farther into the crack. Discard the molding and nails.
Remove the door knob from the utility room door. Undo the screws that fasten the knob plate to the door and remove the plate. The knob and latching mechanism will slip out easily.
Attach a magnetic latch to the door and the door frame. These latches are often used in entertainment centers and other furniture, allowing you to open a door by merely pushing on it to release the magnetic catch. Your door will now open with a push instead of with a knob.
Fill a wallpaper paste tray halfway with paste. Soak strips of paper in the tray.
Cover the door with the first piece of wallpaper. Fold the paper over the edges to completely seal the outside of the door front.
Hang wallpaper on the wall above and around the door, matching the stripes on the wall exactly with the stripes on the door. This will camouflage the door and make it look like part of the wall.
Wallpaper the rest of the room, matching the stripes in the same wall all across the rest of the walls. Allow the paper to dry completely before closing the utility room door.