Playboy Playmate Dani Mathers Warned By Judge, Do Community Service or Go to Jail

Former Playboy Playmate Dani Mathers is slacking ... and the judge let her know it.

Dani was in court Friday where she was supposed to submit proof of more community hours served as part of her plea in her criminal invasion of privacy case. To date, Dani has completed 56 hours but she was ordered to put in 240 hours.

The judge reminded Dani of her obligations and strongly advised her to get on the stick. She has to return to court January 17 for proof of completion ... or else.

As we reported ... Dani chose to do 30 days of graffiti removal instead of serving 45 days in jail. She's also on 36 months probation for secretly taking a pic of an elderly, naked woman in a gym locker room and shaming her on social media.

If she fails to complete her community service, she could get thrown in the slammer for 45 days.