So I sold a Cannondale mountain bike to a nice fellow. After the deal was done, he offerred me a Giant Lite electric bike for free. 2002ish model. He said it wasn't shifting right. I picked it up a week later. Looks like the cable was messed up inside the Grip shifter. Can I replace that 5 speed Sram shifter with any Sram 5 speed? or does it it have to be the P5? P5 shifters are expensive. Regular Sram 5 speed Grip shifters are cheap.

Such as this:

https://www.ebay.com/itm/NEW-Sram-MR...8AAOSwQDhbWsfP

I'm pretty sure I can get this working and shifting properly. I took it for a spin. Batttery and motor are fine....but the shifter would not shift so I was stuck in first.

I have this hub and this shifter:

Can you not replace the cable? Cheaper and easier to find than a shifter.
Or, you could replace it with an inexpensive friction thumb shifter.
Here's a nicer one:https://www.amazon.com/SunRace-SLM96.../dp/B00EHK7PEI
Less expensive: https://velo-orange.com/products/fal...thumb-shifters
Even cheaper: https://www.amazon.com/SunRace-Right.../dp/B001GSSO4E

Lots more to choose from.

Edit: If you are shifting an internal gear hub (not familiar with SRAM) friction shifters are not a good solution.

Yes. It's a SRAM internal 5 speed hub. So I'm just looking for a SRAM Grip shifter with the same 5 speed shifting interval/spacing. Cable end tore up a bit of the inside of the shifter and the grip was all worn anyways.