Nope. She definitely said Teresa Wright. She also mentions it in print if you care to google it. Whether she actually meant Teresa Wright is another matter.
To quote WG:
"Ghost was written for a woman called Teresa Wright, I think. They wouldn’t let me audition for Ghost. It wasn’t until Patrick Swayze said, ‘I am not doing this movie unless you audition her.’ ”
"The trouble is most people are twats or cunts. Or both."

That makes about as much sense..LOL.
Putting race aside, the character in "Ghost" was a small time criminal and had a lot of physical acting to do.
Somehow I think the OP got their information wrong.
The part required a young comic actress, not T.W. in the least.

No. The part was originally written for Eve Plumb, the great star of "Dawn: Portrait of a Teenage Runaway." J.K.