JWoww hired a home improvement contractor to lay tiles at her Jersey mansion, but she kicked him out for being high as a kite ... this according to a new lawsuit.

According to legal docs obtained by TMZ ... JWoww hired Anthony Dai to do some work on her home, but when he got to the job site she claims he was clearly under the influence. JWoww says the contractor was so impaired she asked him to leave when he finally showed up at 10 PM.

And, get this ... JWoww claims the contractor was so out of whack, he left behind his cell phone and wet saw.

In the suit, JWoww claims she gave the contractor a $1,250 check upfront and purchased the tiles herself, but she stopped payment on the check due to his failure to get the job done.

According to the docs, but it was apparently too late -- the dude cashed it -- and the check cashing company sued her for the money.

The good news for JWoww ... the Ocean County Clerk tells TMZ the case has been settled.