Revealing mistake: Casper is shown tying together the shoelaces of the students in Kat's class. When the bell rings and class ends they all get up and fall down. If you look closely you can see that their shoelaces are not tied together.
Revealing mistake: In the scene where Bill Pullman is in his office room, in the mansion, the 3 ghosts lift him in the air, you can see the wires lifting the chair.
Revealing mistake: When Kat goes through the Up and At 'Em Machine, the top comb makes contact with her head, and a few of the comb teeth slightly bend. Thereby revealing that the teeth on the comb are made of rubber.
Answer: It was not Casper (now a ghost of 12 yr old boy) who wrote there was a hidden treasure at Whipstaff Manor. It was Casper's father, Mr. Mcfadden. The treasure in the box is an autographed baseball which used to belong to Casper, before he got sick and died. Mr. McFadden missed his young son Casper, so he invented a machine that can bring a ghost back to life. He considered Casper's baseball a treasure, because to him it is the greatest treasure there is - the baseball that belonged to his 12 yr old son before he died.
Super Grover ★