The worried ghost

Description

On a class field trip to an old house that's now a museum, you don't expect to see what Andy did:
"Andy felt a sudden chill. A hazy white shape was oozing out of the wall--a ghostly form, struggling...
He stared and stared. In New York, in 1976, he couldn't be seeing a real ghost!"
But Andy could! And it was only the beginning...