guessing voltage

I have a light with no markings and a weird connector. Easy enough to rip the connector off and apply my own wires, but I do not know how much power!

I would start low and crank it up. But also it is ultraviolet. So I am not sure how much one could even tell. Any way to determine what is best? Any guesses? I would think 12v but who knows.

But also it is ultraviolet.

I assume it's fluorescent? Are there markings on the bulb? If it's fluorescent there should be a ballast and a starter and these things might be marked.

If there is any other circuitry, you'd also need to know if it's AC or DC.

It might be best to "start over" and re-build the thing with known components....

Why would you "think" it is a 12 volt device ?

Post a photo of it.

Does it look like one of these?:

If it's shortwave UV, don't look at it. It can damage your eyes. Since you don't know, I wouldn't even recommend playing with it.