This is a very simple hook design for 10-12mm diameter outdoor christmas rope light.
The tubular light casing snaps in and stays put. For outdoor application use ABS instead of PLA.
You can fix it with one small screw to balcony railings, walls, etc...
Technical
I used eSun ABS+ filament in light blue, as here in the southern hemisphere the sun is really harsh on plastics during the festive season. (It's summertime! :)
Happy christmas!