Don't Fool With a Phantom - S2-E8
Continuity mistake: Daphne is wearing pink tights at the start of the episode, but when the gang discover that the safe was robbed after freeing Johnny Sands, look at Daphne and you can see her tights are missing. They reappear when we see her with the gang a little later on.
Don't Fool With a Phantom - S2-E8
Continuity mistake: In one shot of Fred, Daphne and Velma at the TV station, you can see there are some lights behind Daphne, but when we see a close-up of her, the lights have gone.
Don't Fool With a Phantom - S2-E8
Continuity mistake: When Shaggy says "What happened?" after the Wax Monster appears, you can see there is a seat behind Daphne, Fred and Velma, but when we see the three in the next shot, the seat has disappeared.
Chosen answer: A ghost wouldn't have to keep any food in the fridge - they don't need to eat. So it is one thing that proves the ghost is not a ghost.