Like the episode "Destination Nightmare," Boris Karloff plays host in an office setting, rather than before a great fireplace. Both were completed in 1959, and became the last to be filmed before production permanently shut down due to lack of funds. The shows never aired at the time because there were only 11 episodes, but by the early '70s, three features were compiled from the series, 4 entries apiece ("Summer Heat" appeared twice). Even series creator Frank P. Bibas discovered this quite by accident at 3:00 AM one night, all done without his knowledge. Till the end of his life, Karloff claimed never to have been paid, although director Herbert L. Strock refuted this.
The plot is very similar to Who Are You? (1960) from One Step Beyond (1959) which aired one after this series in 1959, though the writer was Merwin Gerard.
One of 4 episodes compiled for the feature "Destination Nightmare" - the others were "Destination Nightmare," "The Return of Madame Vernoy," and "Girl on the Road."
Some syndicated cable stations broadcast this episode under the alternate title, "Invisible Ghost."