Testing Neon Lights

[Red01Focus]

Anybody know how to see if they are still good? i helped my neighbor move a bunch of stuff and he gave me some led strips control box and a neon underbody kit but....instead of removing the kit carefully he choose to cut it out so just curious if anybody knew how to test them i don't wanna sell something that doesn't work. if needed i can post pictures of what i have

[Sponsor]

[TerryB]

I've used a 9v battery to test lights. I've also used a 12v battery from my cordless drill.

[Red01Focus]

thanks for the heads up