Camouflage the panel box quickly and cheaply by painting it the same color as the surrounding hallway walls. This makes it much less noticeable to anyone passing through.
Locate the two wall studs on either side of the electrical panel box. Measure the width between the two and the length of the box. Mount a framed picture that’s large enough to hang from the two studs and cover the entire panel box.
Find a vinyl wall decal that’s large enough to cover the surface of the panel box door. Peel away the paper backing and stick in place. Cover the door with a collage of smaller ones as another option.
Mount a framed, lightweight bulletin board that’s larger than the panel box to the wall using Velcro strips on the frame and the wall around the box. You can pull it away when you need access to the box. Use a poster glued to a piece of foam core if you don't want a bulletin board.
Install magnet strips to the back of a lightweight piece of art. Stick the magnets onto the metal electrical panel box door to hide it from view.