In the suit, filed in L.A. County Superior Court, the neighbor says he's bothered by "ongoing and continuing loud and disturbing noises from the property" ... from parties at all hours of the day and night. Baruch also complains about constant noise from barking dogs.

Now here's the rub -- the neighbor says he's fired off at least 7 letters to Wilmer and has made dozens of phone calls to the actor to no avail. Baruch says he's also called the police on several occasions ... and even contacted animal control about the dog barking.

But Wilmer's parties don't stop ... allegedly ... and Baruch claims the shindigs interfere with his sleep.