I had that same piece of metal in mine!!!!! Wtf I thought I was the only one!!!

 

I used a extra long flat head screw driver, you gatta POP it out of its little grove its in. Then I wrapped the same screw driver with duct tape (backwards) and used the sticky side to stick it and pull it out.

 

ok I got a little mirror with a telescoping extension from autozone. was able to shine light and get a good angle for a view. it isn't rubber from spark plug socket, appears to be built up gunk or rust. tried moving around with ice pick but still unable to get bite from socket. I think I'm actually packing it down when I try to get socket on it. I will try to get air hose and try to blow out with compressed air. wish me luck lol!

 

As was stated above you can make a tool to fit over the spark plug and break that stuff up then blow it out with air. Im not experienced in exactly what they used to make the tool but it is basically a hole saw of sorts that fits over the plug.

 

Post #6. Free experience. I imagine quite a few have a scrap piece of plumbing pipe around..or their parents do.

 

SUCCESS AT LAST! I used 3/4 copper pipe that I had from previous job. I scored the end with sawzall. mushed it around a few times then stuck air hose down hole with no fitting, then opened valve and when I looked next all that gunk was out. still was unable to get plug out, either didn't eat my Wheaties or it may have been original. sprayed pb blaster down tube and let soak for about an hour. when I was able to get it about 1/4 turn loose I blew the pb blaster out of the tube. I don't think my rings would like that bath! anyhow running nice and smooth now THANKS FOR THE HELP!