Depends on what you get out of programming, but here's some suggestions:
* Re-create one of your favorite websites or apps
* Create games, these can be as simple or as complicated as you like, and might be a re-creation of a classic (Tetris, Solitaire) or something from a relatively well-trodden genre (visual novels with Ren'py, idle games à la cookie clicker, text adventure games) or something all-new
* Corollary for the above, participate in game jams
* Contribute to open source projects
* Create interesting toys or demos (fractal rendering/zooming, "single-div" CSS demos, fun-looking pixel blotting with SDL or JS canvas, generative art)
* Try your hand at programming microcontrollers for automation, robotics, building keyboard or other peripherals
* Write scripts to automate away boring work, either at home or for your job. You might be surprised how much time/energy you can save by stringing together some python or building some IFTT/Zapier workflows. Automate the Boring Stuff with Python could be a good starting point here.
There are other ideas, but the most important thing is to pick something you find enjoyable, and don't be ashamed to drop a project when it ceases to be interesting.
Some of the most long-lived hobby projects are sustained by just one or two hour nightly sessions, or by weekend hacking.