Schematic of the W3230 thermostat module
This module can be used to switch a load on when a certain temperature is reached. It is sold on major chinese marketplaces. The Voltage for the chip is dropped by the MY transistor. The chip is unknown but it is probably a microntroller with custom software. The temperature is sensed via an NTC thermistor. Reverse polarity protection is provided by "M7F" diode. Please note that diode "W7" is a zener diode (wrong symbol in the schematic).
Schematic of the W3230 thermostat module