Meaning what? There are a plenty of people here who started as cadets including some of the latest joiners.
There is a selection in June so recruitment is on going. On to what terms and conditions I don't know but I believe (not know) it'll be a fixed term (1/2 year) contract.
Recruitment is done by EZS in GVA.
As for how to apply - if you wait for an application online you'll probably be too late.