And officials say it had been there for five years.
Until the boy made his way inside the ramshackle house in Dayton, Ohio, on Sunday, neighbors didn't think anyone lived there, said spokesman Ken Betz from the Montgomery County Coroner's office.
They thought the house was abandoned, and it looked that way.
The front door was papered with citations for the overgrown yard, and no one came and went from the address. The home was unfurnished.
Inside, however, was the body of Edward Brunton, hanging from a rope in the closet.
Betz estimated that Brunton had been hanging there since the fall of 2009, when he would have been in his late 40s, and while it appears to have been a suicide, he said the official cause and manner of his death has not yet been determined.
The closet shielded his body from rapid decomposition, animals and insects, resulting in the mummy-like condition the boy found it in.
"Because of the location where he was found, it was relatively protected, sunlight-protected, temperature-protected and low humidity," coroner Kent Harshbarger told CNN affiliate WDTN.
Brunton died before he could have much contact with his neighbors. He was also estranged from his family and friends, thus no one ever reported him missing, Betz said.
The boy's mother, Michelle McGrath, went into the house to investigate. Nothing seemed out of the ordinary until she entered the room that housed the closet.
"When I crossed the threshold of the room, is when I smelled it," she said.
She called the police.
Authorities found identification documents on Brunton's body. His estranged brother, who still recognized him, confirmed it was him.