What the heck is this?

While driving through a Colorado snow storm recently, my oil light came on slowly and stayed on regardless of engine speed. I checked the level, (it was fine) so I moved the wire going to the sender switch. The light went out, so I assumed the wire was grounding due to loss of insulation. However after the light came back on and I continued to drive, I heard some bearing rattle like a rod was about to go. Today I pulled the pan and found a piece of felt was sucked into the oil pickup. It is about 14” long and about ¼ “ square. What the heck is it and how did it get there? I have 314K on this car and know the complete history. The engine is a virgin so this felt must be some kind of internal gasket or something. Any ideas?

In addition, I used the instructions from the FAQ page on making an engine holder out of 2X6 lumber and it worked great. I did one thing different than instructed though, I took down the sub-frame and left the mounts attached to the block. This way I have plenty of room to swap the bearings and the job is now a piece of cake. Thanks, Brickboard, for all your help.

Jon