That looks to be a Voltage divider setup. The one with markings appears to be a 33 Ohm 5W resistor. If both are the same, then this will provide 1/2 the Voltage of the power supply to whatever circuit it is wired to.
For example, if your PSU puts out 50V, then the Voltage measured from the center junction of the resistors to ground would be 25V more or less. The corrosion at the junction may add resistance and cut that 25V some.