Do 2 wires = 1 input on the keywiz?
No.
Here's how the 40-pin cable works;
Align the connector so the red striped cable is to the left. The red marked wire is +5v (don't strip this one...tape it so it can't short against anything... unless you need it for something)
The next wire is the contact above the +5v. The next one after that is the contact directly to the right of the +5v line, and so on.
There are a number of ground lines that can be used, but these are all common on that board and will be common to all of the switches, so you may uses any or all of them.
RandyT