My cardinal has some white strand hanging out from it's mid-section that just appeared this morning. It doesn't appear to be trying to get rid of it, but it's unusual. Has anyone seen this before?

it kinda looks more like a worm cause if you look at it closly (pardon my french) towards where the tail starts to fork theres a little white bump which could be a segment
Hate to hear that.
But its also normal for a healthy tank to process a dead fish over night,sometimes within a couple of hours if the fish is small enough.