How do you hook up earphones to TV with no jack?

TERK's RF Modulators allow video components such as DVD players, video game systems, VCRs and camcorders to be viewed on televisions that are not equipped with an available audio/video jack.

These used to be available at Circuit City, and you might find them at Best Buy
Or online.

This is what they look like:

TERK MOD-41 - RF modulator prices and availability - Shopper.com