Misfire Cylinder 1

[Someday]

I began experiencing rough idle issues and it took about two days to throw a code.  DTC showed misfire on cylinder 1.  I Swapped coils from cylinders 1 and 3 and cleared the code to diagnose if the coil was the issue.  Took about 24 hours and threw the same code misfire on cylinder 1.  I swapped the plug wires 1 to 3 again and put a new plug in cylinder 1.  After the new plug idle is back to normal and not rough any longer.  Bigger issue is when I pulled plug 1 out there is oil on the plug threads.  I pulled plug 3 to compare and it is dry as a bone.  I’m certainly concerned about the oil on the plug.  Is the oil something I should be concerned with.  I am very suspect given that the misfire was on cylinder 1, and that plug is fouled with oil.  
 

Looking for advice...

 

Truck is a 2012 GMC Sierra with 5.3L vortec with 67,000 miles.  I’ve attached a pic of plug 1.

 

[Jsdirt]

Welcome to the 5.3 oil burner club. A modern GM staple, unfortunately. Mine started at 50k miles. Waiting for the engine to fail any day now, just shy of 100k.

 

There are so many different reasons for these to burn oil, I lost count. Some reasons I didn't even know existed, even after wrenching, and being around people who wrenched on cars for the past 40+ years.

[CamGTP]

Cylinder 7 was fouled on my parents 2012 with only 45k miles because of oil. My mother doesn't floor the truck as much as I do and her daily trip is only 5 miles a day, so it built up pretty fast. I did one spark plug and let it be, ended up trading the truck in on a 2016 but not because of this specific issue.