User blog comment:MisterWoodhouse/Social Activity, the 2010 Editor, and Unpausing Migrations/@comment-45677815-20200930214341/@comment-26939652-20201001143304

I think it inserts a  tag cause your tag starts at 4 spaces from line start in Template:Ghost. But it's a guess.

Edit: Yep, it was. Look at how I fixed it. Generally, you don't want to template tags around your infobox, but outside of them, carefully being aware of any white-space.