A wireless signal device is provided. The wireless signal device includes a device body, a fastening belt, a wireless signal module and a switch unit. The device body includes a through hole. A fixed end of the fastening belt is affixed to the device body, and a free end of the fastening belt is adapted to be inserted into the through hole. The wireless signal module is disposed in the device body. The switch unit is disposed in the device body, wherein in a signal transmission mode, the fastening belt passes through the through hole, and the switch unit is pressed by the fastening belt to activate the wireless signal module.