According to WFLA, Mike Lopez found the box in his grandparents attic in Tampa, Florida.
"It seems as though this belonged to my great-grandparents because there is a picture of them in there," he said.
Lopez said he believes the picture shows his great-grandparents on their wedding day.
Curator of the Tampa Bay History Center Rodney Kite Powell said the map appears to be a treasure map, but was likely a copy from the 1920s or 1930s.
As for the hand, several experts have examined it but no one can say whether it's definitely human.
Lopez has his own feelings about it.
"I think it still looks real, the weirdest thing is the hand," he said.