Fishing Electrical Wires

If you’ve ever had to add a new wire, for an outlet or switch, in an existing wall, this tip will surely help.  One option is to take down the drywall, which is not only time consuming, but also is costly and is messy.  And for running it on the surface, yes it is possible with Wiremold products, but to me, it just looks unprofessional and tacky.  Feeding the wire from a basement, crawlspace, or attic is a much neater solution, but how in the world do you get the wire into the wall cavity?