Private investigator

No. It would be very hard to decide initially whether it is a genuine case or someone who has good reason for being sectretive/not wanting to be found

A lot of abusers use PIs to tract down or keep tabs on partners/ex partners. A lot of estranged family members do not want to be found. Usually the types of people who would use a PI for the wrong reasons can be charming and convincing.

You could also unwittingly end up putting people at risk from organised criminals who aren't old friends at all...

I would struggle to make a living as I would have to be very convinced before taking a job that I was contributing to good not harm

Yes, I think it could be a most interesting occupation sometimes. However, things are rarely as they seem to be in detective stories and dramas on TV and I suspect that the job can be quite boring sometimes when you're just sitting in a car watching and waiting.

In all seriousness, much as I like detective fiction, I doubt I'd be suitable for such an occupation.