The Ghost Detective

In both shows:
> The ML is adorable and a bit of a dork.
> The FL can protect herself in a fight (and the ML, for that matter!)
> One of the leads is reckless while the other is a bit more cool-headed.
> Both leads follow their moral compass, but one of the leads ends up stepping over the line in their search for justice.
> The leads work to stop a psychopathic serial killer.
> FL suffered a loss at the hands of the psychopath.
> Both share a similar issue/tragedy.
> There's a lovable team of misfits trying to stop a big threat.

Both male leads are "coma ghosts" and only 1 person are able to see and communicate with them.

The Ghost Detective is more a thriller/mystery and has a darker tone.
While Ghost Doctor is more comedy oriented and is much lighter in tone.