Hey, yellow-taxi drivers: Stash away your Bluetooth earpiece with your cellphone.

A cabby has been fined $350 for driving with an “electronic communication device” in his ear, although there was no evidence that he was actually using it.

Cabbies aren’t allowed to be on mobile phones while driving, but the Bluetooth-device ban isn’t as well known — even to the people charged with enforcing it.

Last year, an administrative-law judge dismissed an earpiece-violation summons on the grounds that the cabby wasn’t talking on his cellphone at the time. The ruling was overturned on appeal.