This is a screen capture from the snopes urban legend page.
As far as urban legends go this one is a real dud. Of course razor blades have been found amidst merchandise sold at a Wal-Mart store in Lewistown, Pennsylvania! Where else would they keep them? On the roof?
I really doubt there is a Wal-Mart anywhere in the world that doesn’t have razor blades amidst their merchandise. Most of the time they’re next to the shaving cream.
This is really more like “shopping advice” than urban legend.