Spark Plug Rust, Exhaust Leak?

[Benderec]

HI folks. See the attached pic of the #2 plug. Covered in rust/corrosion? All of the others look shiny/clean. Is this being caused by some type of exhaust leak? I seem to recall having a similar looking plug a couple of years back when the #3 exhaust pipe cracked and was making a loud sound. Plane is running fine with nothing out of the ordinary. Could this just be from condensation? Thoughts? Thanks.

 

[ikaros61]

 

[Benderec]

 

[SaltyGator]

 

[magman]

 

[Warriorgreg]

 

[NorthernAviation]

 

[BobW in Tampa]

 

[GM.]

 

[magman]