I don't know if this is off the mark, but two ghost films that feature the
evil (?) or at least scared ghosts of children are Peter Medak's THE
CHANGELING (1979), with George C. Scott, and Robert Wise's THE HAUNTING (1963)
with Julie Harris and Claire Bloom.  THE CHANGELING falters somewhat in the
2nd half, but both are really good pre-POLTERGEIST, non-gross-out chillers.