#1
I have some electro guitar strings laying around .
An i was wondering if they would be good on an acoustic guitar.

They're 9 nickel wound (yamaha , gibson , and earnie ball )

the yamaha inscriptions says they're electric and acoustic , but other two say that they're electric . But they're same size and material , what gives ?
#2
.009's are pretty weak for driving the soundboard of an acoustic. At the minimum you should use .011's. I prefer .012's. They are common, affordable and sound good on a wide variety of guitars. Save the .009's for your electric(if you have one).
#3
You can use them, it won't hurt anything.

Would they be good on an acoustic guitar? I'd say no. Acoustic strings are generally phosphor bronze which gives a lot warmer tone than nickel does. Also, 9 gauge strings don't really give enough tension to drive the soundboard of an acoustic and produce ideal sound, and this would only multiply the tinny sound. But since it's your guitar, I guess its about what you're looking for.

Gear:
Partscaster/Tele into a bunch of pedals, a Maz 18 head, and a Z Best cab.