I noticed this hanging today, anyone know what it is?
No , because it can’t be seen .
That’s a bracket holding the wiring for your Oxygen sensor connection. You need to get this fixed ASAP, it could snag on something and damage both the O2 sensor and the wiring harness, which could be very expensive to repair. I have no idea how it got like this, it doesn’t look that rusty.
It isn’t rusty but it looks like the floor pan it came off of sure is. This could be a Flinstone-mobile in the making.