Who other than my employer is legally entitled to drug test me?

im being threatened with a drug test from some geezor at cadets.. I've only done cannabis once in the last few months.. last weekend..
I dunno if he can test me tho because he aint a doctor or my guardian or nothing so..

He would obviously have to get parental approval... Unless you're over 18?

If you are, they still cant test you without you wanting them too... however, it may be a requirement to continue that particular activity (no one can force you to take a drug test...)

 
You're 18. So it depends on what the age of majority is in your country. It also depends on what cadets is. If that is like a military program, then maybe they have the authority AND responsibility to make sure you are drug free.

I hope you do not take offense,
To that that's gone before;
'Tis only that it's my two-cents,
And not one penny more. §;o)