Not a standard coin.
Tongzhi Zhongbao : 同治通寶
On reverse, the character is anachronistic, only used on the begining of the Qing dynasty.
戸: Ministry of Revenue Mint (戶部局), Beijing, China (1622-1727), followed by 二 which might be the second year.
Not listed as a charm on primaltrek.
Other idea: japanese ?
戸 : door
Some korean reverses are also : 戸八, but vertical :
