The incident came to light after the girl's parents, who had gone out, returned home and found the front door of the house locked, leading to suspicion.
When they peeped in through the window, they were shocked to see their daughter hanging from the ceiling, they said.
The parents immediately informed the police, who rushed to the spot and conducted enquiries.
The girl pursuing her first year BA in a city college was in love with a 22-year-old boy, Mahamuni, from Dindigul.
Unfortunately, Mahamuni died due to electrocution on August 20 and since then Karthika was mentally upset, they added.
Investigation is on, police said.