It’s the runner-up among the films continuing the story of *‘Casper’*, which says something. While *‘Casper’s Scare School'* might have the strongest storyline of the four prequels and sequels, it's held back by animation that is noticeably substandard—and that’s even considering the year was 2006. I noticed some familiar voices, including Kevin McDonald (who voiced Pleakley) and John DiMaggio (known for Bender).…