Somehow I don't think this was the treasure he was digging for.

 

A man in Lower Township was digging in his backyard, only to find a live cannonball.

 

According to The Press of Atlantic City:

'Police responded to the 200 block of West Bates Avenue after a man digging in his backyard found what police described as a live cannonball.
 
 
The device had a brass cap on it. It was stamped, “4k, 85mm”, according to police.
The Atlantic City Police Bomb Squad removed the cannonball and detonated it in an unpopulated area.'