A competitor uses a fake address or fake name on Google

a listing at an address where the business isn't (an empty lot, a mailbox store, a home with no sign), or a name stuffed with words like "Best Plumber Skokie".

1. Check calmly: drive by or look at the street photos. Is there really no business there?
2. On Google Maps, open the listing, choose "Suggest an edit" and correct the name, or report the place as not existing.
3. If that doesn't work, Google has a "Business Redressal Complaint Form" for listings that break its rules. Search for that name, and add photos and links as proof.

post fake reviews on their listing, or add keywords to your own name to compete. Both can get your profile suspended.