Evelyn: maybe this will help
Projects from Hometalkers
Hi Evelyn, this is a great looking one for you to check out, hope you like it!
If you cut into the walls, you must line them with timber frame..............
here are ideas for you
Here is an idea that could maybe work: https://www.youtube.com/watch?v=Oqsbl9lV6Xc
Here is some on the wall storage- https://www.hometalk.com/44285870/garden-tool-organizer-for-garage
As in inside the wall cavity? On an inside wall that doesn't contain wiring or pipes you can cut the wallboard out between studs, frame it, and add shelves. Good luck and stay safe!
In-wall as in recessed storage space in between the wall studs?
Here are some examples:
this is how we added little shelves inset in our drywall between 2 studs - https://www.charlestoncrafted.com/turn-old-medicine-cabinet-open-shelving/
Locate the studs and cut out between them. The add wood using stud boards for shelves. You can paint the backside of the other wall board or add contact paper or wall paper. Frame out the area for a finished look.