i dont know what this part is, please help
 

https://cimg7.ibsrv.net/gimg/www.rx7...5232a69826.jpg
https://cimg9.ibsrv.net/gimg/www.rx7...e3061cb381.jpg
https://cimg0.ibsrv.net/gimg/www.rx7...38a9133272.jpg
https://cimg3.ibsrv.net/gimg/www.rx7...dabae61b41.jpg
https://cimg6.ibsrv.net/gimg/www.rx7...b6ee0a84f7.jpg
https://cimg8.ibsrv.net/gimg/www.rx7...3615a116a6.jpg
https://cimg2.ibsrv.net/gimg/www.rx7...c2ff10d681.jpg
https://cimg1.ibsrv.net/gimg/www.rx7...1bfade643c.jpg
im new to cars and i dont know much, i went to autozone and they didnt know either. ive got an 87 rx7 and it has had a few previous owners so i dont know alot of what they did to it. if anyone knows what this is and what the wire is called please let me know. the bolt screws into the threaded part in the first pic and the wire was connected to the bolt, the wire was all melted and rotted so i removed it and now i have no idea what it is.