What kind of electrical outlet is this? (Old home)

The outlet is loose and I would like to at least fix that. But I have never seen something like this before. Attachment 39127 (http://www.doityourself.com/forum/attachments/electrical-ac-dc/39127-what-kind-electrical-outlet-old-home-10387313_10154678806990010_410645643516348757_n.jpg) Attachment 39128 (http://www.doityourself.com/forum/attachments/electrical-ac-dc/39128-what-kind-electrical-outlet-old-home-10387475_10154678806985010_8388430111603598094_n.jpg)