From The Perry Mason TV Show Book (Revised)
This is a strange episode.

Bruce Chapman returns home early from a business trip to find that his wife, Marie, wants a divorce. Chapman is upset and very surprised. Just before he had left for his trip, he thought he had found the strangled body of Marie in her cabin. He thought someone had done him a favor, and hoped the matter would be cleaned up before he came home. But now if Marie is still alive, who was that dead woman?