The ghosts in this short strongly resemble the ghosts in the 1937 Disney short, "Lonesome Ghosts."
The ghosts sing about the Flora Dora Girls, the title of a 1930 film that featured somewhat risque (for the era) dancing girls. The adult cinema audiences would have appreciated such inside humor at the time.
At the time of this short, a cinema show usually included an organist playing popular songs for a sing along. This was a leftover from the silent era, when live organ music often accompanied the feature film.
Disney would incorporate a haunted organ (and player) in its Haunted Mansion attraction some 60+ years later.
The haunted house bears a striking resemblance to the one shown in the horror classic "Psycho" over 20 years later.