With a supporting cast including Marie Lohr (who I liked in Went the Day Well? (1942), review here),Yvonne Arnaud and Wilfrid Hyde-White, this film manages to be eccentric and humorous utilising the fairly limited special effects of the time. However, that said, it is a little choppy, as over 200 years pass before the soldiers are finally allowed to leave the house. As a consequence, characters come and go quite rapidly and the fun mostly stems from wondering how they'll accidentally sabotage their latest efforts to be set free. My favourite of these was the Great Exhibition period where they become a spectacle so convincing that a scientific expert believes in them enough to recommend that Prince Albert does not visit the show - for fear of looking like a fool to his own society.
The Ghosts of Berkeley Square takes a liberal approach to haunting. The soldiers can materialise, blend into their surroundings, get into trouble with humans and make mischief throughout. Plus, a great number of the people they come into contact with are surprisingly unperturbed at the idea of ghosts. The film necessarily relies on the charisma and interplay between the two ghosts themselves and Morley and Aylmer bounce off each other fairly neatly throughout, even during the scene where it's revealed they haven't spoken for over half a century because of an argument.
This isn't a spectacular film but it's amusing and very of its time with some flippant racist comments which make make the contemporary viewer cringe. Still worth a watch if it's on though.