wrote:
Why don't they make 4 wire Romex (plus ground).
There are many 2 or 3 way switch circuits that need 4 wires plus the
ground. 3 wire is all they sell. I can think of other cases where I
could use 4 wires too. For example, I had to run two common strands
of romex to a double light switch that also feeds an outlet. Two
switched wires, one hot, one neutral. That's 4 wires. So now I have
an illegal white wire controlling a light from a switch. Why not 4
wire romex with black, red, blue, and white. (patriotic too).

I googled "4 wire" romex and got:
Results 1 - 10 of about 4,670 English pages for "4 wire" romex

This was from the third hit (part way down the page)

We have what I call 12/4 Romex. Red, Black, and 2 White in romex. We
use 3 or 4 wire home runs whenever we can.
www.BrooklineElectric.com
415-239-5393
John A. Peters, Electrician SF


Lou