13 GhostsGoofs
Continuity
When Medea and Rush are looking at the portrait of Dr. Zorba, Medea is holding her hands behind her, but when you see their reflection in the glass of the painting, Medea's hands are in front of her.
After the Ouija board scene, when Hilda Zorba is shown in bed (at around 58 mins), she's sitting up with her knees pulled up towards her chest, but in the close-up (from 22:59 to 23:00) she's leaning back against the headboard. Then in the next shot (at around 1 min), she's in the original position.
At 1:19:00 the boy is placed on the bed to be suffocated by it. His body changes positions throughout the scene.
Factual errors
When Buck is playing with The Great Shadrach's (the lion tamer's) props, he opens the cage then puts on the glasses. The image of the lion is far larger than the cage which supposedly contained it. Granted that a ghost need not be subject to physical limitations, the cage could not have contained a live animal that size.
Incorrectly regarded as goofs
When Buck puts on the glasses and sees the lion, its roaring is not synchronized with its mouth movements (from 51:59 to 52:05). This could be a ghostly phenomenon chosen for its spooky effect.
Revealing mistakes
After Buck slides down the banister and walks off, we see money fall to the floor. It's clearly noticeable that the money didn't fall out of the hidden area in the stairs. If you look closely you can tell that it comes from somewhere above the stairs.
At approximately 44 mins into the film Dr. Zorba is investigating his dead uncle's bedroom when eerie wind blows through and blows out all the candles. Then one by one the candles relight on the candelabra. One candle floats up on its own from the candelabra with its shadow cast upon the wall. As the candle floats an occasional glimmer of the filament used to "float" the candle can be seen; as the candle returns to its place in the candelabra you can see the shadow of the filament cast upon the wall.
In Rush's office we see the fly buzzing around the glasses. After it gets zapped (at around 33 mins), it still keeps moving.
Miscellaneous
When Buck blows out his birthday candles there are 11 of them, but the following day in Benjamin Rush's office, his mother refers to "our 10 year old son".