A broom hanger using a simple cam mechanism. No bolts required.
To give the cam grip I added some stick on foam.
This one is printed in 0.25 layer height with 0.15 infill in PLA and it seems plenty strong enough.
It is designed to be mounted with 6g 30mm screws.
UPDATE: Added base v2.stl. This one has a stronger pin.
Note: When you load this into your printing software you will need to rotate 90 degrees on the X axis.
Print it out, add some self adhesive foam to the cam so it grips. Alternatively you could print the cam in a Arnitel or maybe Ninja Flex so it grips.
Attach the cam to the base and mount it to the wall. Make sure the cam moves freely on the shaft. The cam should fall down when there is no broom in it.
Then stand back and marvel how good your 3D printer is! :-)