Diagnosis
That's most likely the evaporator fan motor. It's mounted in the freezer compartment behind the back panel and can get iced up or the bearings can wear out, causing a racket.
How to Fix It
First, unplug the fridge. You'll need to get into the freezer. Remove the back interior panel – it's usually held by a few screws. Once it's off, you'll see the fan. Check for any ice buildup around it. If it's iced, you've got a defrost issue, but clearing the ice might quiet it for now. If it's clear, try spinning the fan blade by hand. If it's stiff, grinds, or wobbles, the motor itself is shot. Replacing it is a straightforward swap: disconnect the wiring harness, remove the mounting bracket screws, and put the new one in.
If That Didn't Work
If the noise is more of a low, rhythmic hum or vibration, check the condenser fan down by the compressor at the bottom rear. Something (like a wire or a piece of packaging) might be touching the blades.
Heads Up
When you order a replacement fan motor, you'll need the exact part for the MFI2570FEZ. The one in the freezer is different from the condenser fan. Getting the model number right saves a return trip.