66 wiper switch help

I am restoring a '66, which I inherited 1/2 way through the resto. Needless to say I have a lot of puzzles to solve. Most I have, except for the wiper switch. What I have is the front half of a wiper switch (knob, bezel, cup washer and housing...minus the guts that actually have the male plugs) and I have a random switch that came from who knows where. It has the "guts" and a screw on bezel with no lettering in it, and the bezel is different from anyother mustang bezel I have seen (it doesn't go with this car) . The odd one you can click left or right and pull, like a single speed wiper switch. It has 4 male spades on the back.

What I need to know how to figure out is if I need to buy a single or a 2 speed wiper switch. Is there any way to tell? I have looked at the back of the single speed switch for a '66 and it looks different than my plug. The plug has 4 female spades, but in a very wierd pattern (nowhere near the "odd" switch that I have). Is there any help, or any markings I can look for that will tell me if I need a 1 or 2 speed.

Thanks in advance.

It is in kind a cursive '"z" shape, but not really and I guess there are 5 slots, but only 4 wires going into it. The guy before me might have cut one of them (he did this quite frequently)

Thanks for the quick reply.

I think I got it now!

Ok, I did some more digging last night and here is what I think is going on. I think I have a single speed wiper switch (the harness looks like a question mark) since all the colors of the wires are right. What was stumping me was why there was a black/white wire next to it that runs to the washer pump, then a white wire coming off the ignition switch post. Well that white wire has an inline fuse and an exposed ring terminal (don't think ford would do this) and it his me. The wire running to the pump isn't in the right place (not loomed, just poked through the firewall). The guy before me must have had an aftermarket switch that he rigged up to add windhield washers. Also contributing to my theory is the fact that the pump is there, but no washer bag, bag hanger, hoses, or washer nozzles. I had assumed he ripped them out. Nope, they probably were never there.

So, would adding a push button switch be the only way to add washers to a single speed switch? From the wiring diagrams I have it looks like the single speed never had a washer pump hooked up on that car.