Sticky Rocker Light Switch -- Not stuck, just sticky -- fix or replace?
That's not the kind of device that you'd attempt to repair. For one thing, you'd void the UL listing and assume liability for any resulting damage, injury, or death in doing so. For another, parts aren't available. For one more, they're far too inexpensive to waste any time on.

Buy a new switch. Turn of the breaker. Replace it in the same configuration following standard good wiring practice. Be happy.