The Sixth Sense Movie Wiki

The next autumn, Crowe begins working with another patient, nine-year-old Cole Sear (Haley Joel Osment), who has a condition similar to Vincent's. Crowe becomes dedicated to the boy, though he is haunted by doubts over his ability to help him after his failure with Vincent. Meanwhile, his relationship with his wife has deteriorated to the point where she ignores him and refuses to talk to him. Crowe believes that she may be contemplating a romance with a coworker who keeps coming around the house although this elicits sadness from him not anger. Crowe also repeatedly has difficulty opening the door to his basement office.
Once Crowe earns his trust, Cole eventually confides in him that he "sees dead people... walking around like regular people". One ghost who appears to Cole is an overworked wife, abused by her husband, who has slit her wrists. Another that tries to hurt Cole is only heard as a voice who pleads with Cole to let him out of a dark cupboard, then yells that he didn't steal "the Master's horse" and threatens to attack Cole. A third ghost is a boy with a large gunshot exit wound on the back of his head who asks Cole to come with him to find his father's gun.