Officials said the shooting happened on August 19 at the home a member of the Kenosha Police Department.
A 9-year-old allegedly accessed a locked gun safe and got a handgun.
The sheriff said the handgun was "accidentally discharged."
The child had minor injuries to their hand, the sheriff's office said.
The handgun was not the Kenosha Police Department member's duty firearm, the sheriff said.
No other information was available.