Anything that is visually lesser or pastel would be call 50% possible het Ghost.
If it was Ghost then no other possibilities would exist.
If it was normal looking the best odds you could list it as is 50% possible het Ghost.
Now if you have Ghosts in the clutch and no lessers or pastels the odds are in your favor that the ghost is probably the father of all the offspring and they are all 100% het ghost, but you can not gaurantee that. So if you sell them as a principled person you would have to list them as 50% possible het ghost, unless you kept them, raised them up, and proved they were het ghost through breeding.