Playboy Playmate Cassandra Lynn Hensley Found Dead -- Overdose Suspected

Playboy Playmate Cassandra Lynn was found dead in her friend's L.A. home Wednesday ... and police are investigating the death as a possible overdose, law enforcement sources tell TMZ.

We're told Lynn's friend found her floating in a bath tub. The friend then called police, reporting a possible OD. When paramedics arrived they could not revive her. Foul play is not suspected.

Lynn -- Miss February 2006 -- was 34.

Cassandra was pretty active on Twitter ... her last real tweet was three days ago.

Her Twitter updated automatically with her horoscope ... her latest reads: "Unspoken obligations prevent you from doing what you wish today ... No matter what you do now, you might not feel completely fulfilled. Working harder isn't the answer, but neither is escape." Eerie.