The best thing to do is to SOS chain for a hidden ability Pangoro on route 10, 11, or 17 (note that it cannot be found on r.17 in USUM, only in SM). Use a Pokemon with Skill Swap or Trace to check the Pokemon's ability.
At a chain of 10 - 19 you have a 5% chance of finding a hidden ability Pokemon.
At a chain of 20 - 29 you have a 10% chance of finding a hidden ability Pokemon.
At a chain of 30 - 39 you have the best odds, a 15% chance of finding a hidden ability Pokemon.
Pangoro's hidden ability Scrappy allows it to hit Ghost-types with normal type moves, so it can false swipe a Ghost-type easily. Dedicate some time to chaining it or you can go online to trade for one.
Good luck!