Stranded vs. Solid Wire 

One more thing to keep in mind is to select the style of wire that best fits your needs. Some wire is stranded, while other wire consists of a solid copper conductor. In installations using metal conduit, the solid wire doesn't always pull as easily if the conduit has a large number of bends. But solid wire is usually easier to secure under screw terminals, such as those found on standard switches and receptacles. In standard usage, though, the wire conductors in conduit or JVC cable for household wiring will be 14-, 12- or 10-gauge wire that is a solid copper conductor.