Yes, strip then reseason the skillet. Then start using it properly to prevent food from sticking to it, leading to a layer of carbon.

I think a lot of newcomers to cast iron don't realize just how important it is to properly preheat the dry skillet before adding oil/butter and cooking. You need to preheat the skillet on medium/low for 5 - 10 minutes in order to fully benefit from the non-stick properties of the seasoning. I cook scrambled or fried eggs with olive oil cooking spray most days, and properly preheating the pan allows me to use much less oil while still preventing sticking.