CAUSE FOR ALARM!(1951)
In the set: 100 Greatest Mystery Classics

A man believes his wife and doctor are trying to
kill him! So he sends a letter to his lawyer to
let him know! Shortly after having an attack of
some sort, he tells his wife of his suspicions
and threatens to shoot her, but collapses and
dies! Now his wife has to try to intercept the
letter to save herself! B-

A review from IMDb.com:

This film must be what passed for a 'chick flick'
in the 1950's. It helps if you are a Loretta Young
fan, and their are many of us. She is ably supported
by Barry Sullivan and by the capable direction of
Tay Garnett. Maybe 'tense drama' would be a better
way to describe this picture as it barely falls
under the heading of Film Noir - no violent
confrontations, no dark, wet back alleys here,
just sustained suspense, especially in the second
half of the film. Miss Young is in almost every
scene and the production seems almost stage-bound
as it takes place mostly in the home of Young
and Sullivan, with a few exterior shots thrown
in.

Still, Miss Young gives a good performance and
the movie holds the interest throughout, and is
very worth watching. - GManfred