Bela Lugosi is more genre-cast than type-cast in this film. While it's still a suspense thriller, he is for once given a sympathetic role, he he plays it to the hilt, giving a very sympathetic performance as a man devastated completely after being left by his wife. It's both a strength and a flaw in entertainment terms, though, that the script of this film is utterly strange and bonkers. Lugosi's wife has lost her memory and sanity, and is being fed and hidden away by Kessler's (Lugosi's gardener). She likes to wander around at night in a spectral fashion, whereupon Kessler has a tendency to see her, then go temporarily insane and kill somebody. On this occasion, he kills the crazy ex of his daughter's fiancé Ralph, causing Ralph to take the blame for the murder and be executed. Then Ralph's twin brother shows up from abroad and help investigate the murders.
Yes, it's that odd a plot. Which makes it totally unbelievable, but also loads of fun to watch. I liked that it depended on psychological horror, and that the "Invisible Ghost" of the title was invisible because there wasn't one.
While I'm sure the direction was done under time constraints, there are a number of nice shots, and Joseph H. Lewis conveys a lot of information evocatively and visually in a scenario that requires a lot of information to be transmitted quickly.
All in a all, a good showcase for Lugosi in what's actually rather a tragic and sympathetic role, and some nice creepy film-making around a scenario that's completely ludicrous -- but entertainingly ludicrous!