Question

Why halock wanted helen to disappear before his wife arrived?

Answer 1

John wanted Helen (the ghost) to disappear at once because he did not want Lavinia to see Helen, the ghost. She was a very sensitive woman and subject to hysterics. She usually could not stand the sight of a mouse, just imagine what the sight of a ghost in the living room would do to her!

This shows Lavinia was quite a timid in handling ghosts and mice.