Delivery Man

They both involve using supernatural powers to discover a serial killer. There is a similar dynamic between ML and FL but reversed. Similar balance of humor and seriousness.

Male lead providing services to ghosts instead of living humans.
Both are romantic comedies with ghost involved, gives off very similar vibes.

The main element of the show is tied to the mobile cell phone which is needed to communicate to the human world to solve the protagonist predicament ......

Each has a ghost needing to find answers. Both also have a scene that reminded me of each other. In Dear Prince ML ghost is pulled to FL on scooter since tethered to fob & in Delivery Man FL ghost gets pulled to car as if tethered to it.

I haven't seen this recommended yet, but it also has the same plotline where the ML solves the last wishes of the dead and makes a business out of it.

both shows have living humans help ghost go peacefully into the afterlife. Humanistic feel and touch for a lovely ending just like S1