I have a switch that doesn't want to shut off, and now that it does, only some of the lights are coming back on. The recessed cans on the switch work but another ceiling fixture doesn't. I took the cover off the switch and noticed the ground wire wasn't connected to the switch and the red wire sparks. Is it just a bad switch? Or is it a fried light fixture and a bad switch?

Start by replacing the switch to eliminate the sparks, you don't say where the sparks are being created, but I assume at the screw terminal.

Since some lights are working, could be a coincidence that the fixture has a separate problem, check the fixture after replacing the switch.