I apologize if this was covered and I could not find it, but after 6 pages using search terms "oil pressure switch", I started adding to the frustration I was already experiencing.
My poor old truck started "bleeding out" around the oil pressure switch, I do know where it is located and already bought a replacement part.
Since my Awesome tool collection happens to be in storage 325 miles from where I am, I am forced to purchase a socket needed to remove the Factory unit. I called the Ford Dealer, and the best news I got from him was that the replacement part might take a smaller socket, (Duh.... No Shit dude, I already found that out.) but he only knew it may be Metric or it may be SAE. (Glad they don't use British measuring units anymore..)

Does Anyone have a clue as to What size socket I need to remove the Original oil pressure switch?

If you missed it in the title, it's a '98 4.o liter. If you caught that, sorry for the redundancy, but after working from 9 p to 6 a, and walking the 5 miles home just to crawl under the truck with a very limited tool supply, I'm a bit fussy.

I figured it best to get this fixed before the grand kids get home from school, as I don't wish to add to their vocabulary.
Thanks in advance for ANY help.

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Black '98 XLT 4.0 liter, super/extended cab, 4X4, 5 speed manual

*Mods & Pseudo Mods*
Sony head unit, Expo OHC, Uniden CB, 16" Wheels from a 2002 Expo Sport Trac/255-0R16 tires

Well Since My frustration lead to impatience, I grappled the damned thing out with an adjustable wrench. ( the ultimate PITA method )
As luck would have it, that wrench has SAE markings on one side, and Metric on the other. According to those markings, the size was dead on 26 mm, and a little over an inch, but less than 1-1/16th. Of course I could never guarantee the accuracy of the wrench, but if you happen to have your awesome set of tools closer than a 6 hour drive, you should at least be in the ballpark.

Since I answered my own question, I have no problem if a moderator may feel this thread is now a waste of bandwidth, and delete it. just PM me to let me know.

B.T.W. Both units sold at AutoZone takes a 7/8" socket.

__________________
Black '98 XLT 4.0 liter, super/extended cab, 4X4, 5 speed manual

*Mods & Pseudo Mods*
Sony head unit, Expo OHC, Uniden CB, 16" Wheels from a 2002 Expo Sport Trac/255-0R16 tires