If you play Switcheroo from hand, do you get a draw with Yordle Explorer?

Yes, you draw a card — Yordle Explorer triggers when Switcheroo is played from Hidden.

Yordle Explorer checks the printed Power cost on the card, not what you actually paid. Switcheroo has a printed Power cost of 2 (A A), so it satisfies the "cost 2 or more" condition even though playing it from Hidden costs 0.

This is the same principle as Lux triggering on discounted spells or Yordle Explorer triggering on cards with Repeat — the printed value is what matters (FAQ #6912, confirmed by #8453 and #8807).