Oil pressure switch and light

Can anyone tell me what size socket is required to get my oil pressure switch out of the housing ? This is the unit behind the ignition cover and below the pickup coils. The biggest socket I have is 19mm and the switch is way bigger,
24mm maybe. I'd like to take a good look at the unit.

The same part is found in some 1300s, a few 550s and looks like lots of 650s.

Background.
I went to take the bike out on Saturday evening but the oil pressure light stayed lit. So I parked the bike and it was Sunday night before I could take a look. I took the points cover off and the pickup coil plate and the automatic advancer. Disconnected the wire going to the pressure switch but couldnt get the unit out. Not much room in there to manouver an adjustable wrench. I ended up just cleaning the top of the switch and reconnecting the wire and lo and behold when I put everything back together my problem was gone and the bike fired and the oil light went out.

So ... probably just some dirt causing a short but I'd still like to take the switch out and give it a once over and maybe see if I can check for oil pressure.

Thanks

Same setup on my KZ750. Mine was dead and leaking. Getting it out was one of the biggest pains I have run into on that bike. Even with everything removed (including the advancer unit) I couldn't get a socket and rachet in there together. Had to use a vice grip held at an angle and turned with a screwdriver blade. if you install a new one, use some Locktite if you can't get it very tight with a wrench. That should hold it and seal it too.

I was afraid of that
Was hoping I could get a socket which would fit and use an extension rod to the ratchet. I'll probably try the vice grips at the weekend but if it looks like I'm going to b****r it up I will leave well enough alone.

6" cresent wrench is about right size

Seems to me I tried a 6" cresent and either it wouldn't fit, or wouldn't turn very far, but your milage may vary.

flip it over! :laugh:

A 26mm socket for anybody interested
I also needed to buy a 3/8 to 1/2 inch adapter. Total cost about $6 at Princess Auto.
Came out easily and I did'nt have to bu**er it up by using a crescent wrench