I'm looking to replace the oil pressure switch on my 1995 F150 with a 5.0, but when I look up replacements I either get

This 1995 FORD F 150 Motorcraft E4ZZ9278A Motorcraft Oil Pressure Switches | Summit Racing (I know this one requires an extension in order to fit)
Or this
It seems wherever I got I can't get a firm answer on the difference between these two. I've seen posts about one sensor requiring you to short a resistor in the dash, but then again there's no clarification.

 

Your truck came stock with the oil pressure switch, like in the Amazon ad. It's an on/off switch, which closes at around 5 PSI and moves the analog oil pressure gauge to somewhere in the "normal" range. Ford did this to reduce customer complaints about low oil pressure.
The motor craft part you posted is an actual sending unit, designed to send a varying signal to the analog oil pressure gauge, and requires a nipple to space it out off the engine block. If you install the motor craft sending unit, you need to modify your dash gauge with a resistor, so it will work with the sending unit.

 

Awesome, thanks for explaining it. I was really trippin out trying to understand which was which. My oil pressure gauge keeps moving around between N and R (of normal) sporadically so I'm thinking it's shot since it hasn't done it all winter, and my oil pressure itself is fine.