How dangerous is it?
I had one of those spongebob pineapple house decorations and at the top, it had a small piece of what I thought was plastic sticking out where it wasn't supposed to, but I just thought it was a defect in the way it was made... Then I noticed some strange brown growth on the decoration, so I took it out, scrubbed it off and noticed that there was more brown stuff at the base of that "plastic thing" sticking out.
I tried to break it off to clean under it and it wasn't what I thought it was... It was a small metal wire that was covered in paint so I couldn't tell it was metal. Needless to say, the decoration has been removed... But it was in there for like a month and a half.
What harm does rust cause?