You should have been notified of probate. You can always check online at the Wayne County Probate Court to see what has been filed. If there was no will, you are correct. Something sounds fishy and you should certainly look into matters. Visit www.kliszlaw.com to discuss in detail. Tim Klisz
I agree that you should check the Wayne County files to see if anything has been filed. If it had been, you would certainly have been notified. My suspicion is that the assets may have been jointly owned or had beneficiary designations. For that reason, probate was never filed, nor was it required to be, strictly speaking.
If there was truly cash sitting in those boxes, then there is an argument that it should have been in a probate estate.
You need more information before being able to decide how to proceed. The apparent size of the estate suggests that it would be worth looking into further, however.