Connecting Optical Fignerprint Scanner with Raspberry Pi?
According to this, it looks like this module is basically the same as the one sold by Adafruit i.e. the R305. This is a Python library for it. Only other thing is to figure out the pinout. 

It should be a bit easier to identify GND since most capacitors will have one terminal connected to it. The module interface is UART, based on other similar modules. This is a link to the datasheet of the BR6210 MCU that seems to be running the show.

Its pinout is there and with any luck, the UART used for the interface is one of the MCU's hardware USARTs (USART0 - 2) and not something bit-banged. The pin descriptions say DIO1 is RX and DIO2 is TX. MCU pins seem to be 5V tolerant based on its Vih values. So the MCU UART is possibly connected directly to the header pins, in which case you can easily use your multimeter to find out which of the 3 USARTs is connected to the header and to deduce which header pin is TX or RX. If that doesnt work, then they probably did some level-shifting through some of the resistors there; you can also use your meter to check if any of them are connected to both the header pins and the MCU USART pins.

One terminal of that fat capacitor C2 is probably connected to a power +; could be the MCU 3.3V or the header 5V. If its connected to the MCU 3.3V it can lead you to the 5V VCC header pin through one of the 3-pin components that look like regulators near the header.

With those 4 pins identified (Vcc, GND, TX and RX) you can run a basic example from that library to see if its all good.

Or you can just buy a better documented module like the R305 or FPM10.