To Boo Or Not To Boo (1951) - Casper, The Friendly Ghost Theatrical Cartoon Series

Surprise ending to this one

I'm not sure if this is the right episode but the synopsis is similar.

Casper happens at a halloween dance held in a barn. He finds some white paint in order to attend the party in an effort to avoid scaring people. While there, he befriends a little girl and general merriment ensues.

At one point, Casper attempts to bob for apples but the water from the barrel washes the paint from his body. The usual "Yikes! it's a ghost occurs and everyone runs away.

SPOILER...........










Except for the little girl! Casper enquires as to why she's not afraid of him. She replies: "Because I'm a ghost too!" Suddenly, she glides out of her body revealing herself to be a female version of Casper.

The ending was somewhat shocking and carried some psychological impact on me as a youngster when I first saw this one.