If you have some old item in the home, which no longer serves its purpose, then you can reuse it for something else. It is always better to repurpose old things, to recycle and reuse them, than to throw them away. So that way, you will save your money, and your home has some original DIY decorations. Your guests and visitors will be impressed, and you will be proud of your work.
The process should start with opening the guitar and you will attach a board in the middle that will serve as a shelf where you can put some items. You can put more shelves, depending on your wishes. After that, you can re-paint it, or leave it in its original finish. Then attach it to the wall and your guitar shelf is ready. On your new shelf, you can put whatever you want. See some interesting guitar shelf designs that will attract your attention for sure! Have fun and be productive!