Street Artist Mr. Brainwash -- I Ain't Banksy ... But I Am Single

Unfortunately for Mr. Brainwash life is not imitating art these days -- the eccentric graffiti artist famous for his “Life Is Beautiful” tag ... is in the middle of a divorce.

Mrs. Brainwash ... who actually goes by Debora Guetta ... cut bait on their almost 19 year marriage, citing irreconcilable differences in divorce docs filed last month. She says they separated on April 20.

Debora is requesting spousal support from Brainwash -- who starred in the 2010 Banksy doc, "Exit Through the Gift Shop." She also wants sole physical and joint legal custody of their 13-year-old son. She's cool with Brainwash having visitation.

As far as assets go -- no details in the docs, but keep in mind some of Brainwash's pieces sell for well over $100k ... so chances are there's some cash to split up.

The biggest tragedy here ... we still don't know who the hell Banksy is!