She has hired her female driver as a bodyguard and moved her into the 10-bedroom home to be by her side 24/7.
The scared "Someone Like You" superstar told a pal, "I'm not rattling around here on my own. It gives me the creeps."
Adele, 23, was spooked after "hearing things that made her jump" at the $11 million home, set in 25 acres in rural southern England.
The London-born singer vowed never to spend another night there on her own.
So she is paying the bodyguard, said to be a down-to-earth former chauffeur in her 30s, £100,000 a year to stay with her at home and to accompany her around the world.
Adele's mansion boasts 10 bedrooms, an indoor swimming pool and a tennis court.
The mansion, which has two swimming pools, used to be a convent and has a private chapel.
"Adele was so excited to be renting such a lavish property but it has not turned out as happily as it should have," the friend added. "She is convinced it is haunted. She knows about its religious history -- and it's a big place to be in on your own in the dead of night."
The singer -- who picked up six Grammys and two Brit Awards last month -- has also hired two other full-time security staff.
They will guard the gates of the £15,000-a-month mansion after she discovered a public walking trail runs past her front door.
"She can see the funny side but she is a sensible girl and knows there is no point taking chances with her safety," the friend said.