EXCLUSIVEKeeping up with household bills can be a bitch ... even for billionaire heiress Petra Ecclestone Stunt -- who lives in one of the most famous mansions in Bev Hills -- but allegedly stiffed her electricians.
Petra -- the Brit party girl who bought the Aaron Spelling palace for $85 million a few years back -- just got hit with a lawsuit from Sun Electric ... which claims it installed kitchen lighting, security cameras, and enough power for a Griswold-esque Christmas light show.
Sun Electric says it got a partial payment, but Ecclestone still owes more than $107K.
The company is well aware of Petra's deep pockets too, pointing out in the docs obtained by TMZ -- she has a $3 billion trust fund, and is only known for "wealth and extravagant spending."
Ecclestone hasn't gotten back to us with her side of the story.