The actress, who acted in critically acclaimed Bollywood film BA Pass, reportedly ended her life by slashing her neck with knife.
According to the police Shikha committed suicide following depression due to lack of employment.
Shikha, arrived in Mumbai from Delhi two months back, lived with a friend in a housing society in Andheri West.
As per an Indian Express report, Joshi locked herself inside the bathroom, taking a knife along, at 6.30 pm on Saturday.
"A few minutes later, the roommate knocked on the bathroom door asking Joshi to come out. The roommate asked Joshi why she was taking so long inside. When Joshi did open the door, her neck was covered in blood," Ravindranath Pawar, senior inspector, Versova police station was quoted as saying.
She was rushed to the hospital where the doctors declared her brought dead.
Police have also registered a case of accidental death.
Shikha was also a member of the Aam Aadmi Party (AAP).