The Fridgularity (2012) by Mark A. Rayner?
Blake Given’s web-enabled fridge has pulled the plug on the Internet, turning its owner’s life – and the whole world – upside down.
Blake has modest ambitions for his life. He wants to have his job reclassified, so he can join the Creative Department of the advertising firm where he works. And he wants to go out with Daphne, one of the account execs at the same company. His fridge has other plans. All Blake knows is he’s at the center of the Internet’s disappearance, worldwide economic and religious chaos, and the possibility of a nuclear apocalypse — none of which is helping him with his career plans or love life.
The Fridgularity is the story of a reluctant prophet, Internet addicts in withdrawal and a kitchen appliance with delusions of grandeur.
The entity "steals" the Internet so I'm assuming it has some kind of control over electronic devices. This review explicitly mentions the protagonist being "chosen" by the smart refrigerator:
In Mark A Rayner's newest release, Fridgularity (a satire on technological singularity), that is exactly what is happening when a web-dependent generation is suddenly and horrifically without internet. An end-of-the-world panic blankets our Canadian characters with fear and a geeky corporate boy named Blake Givens is chosen by the bi-polar internet-stealing entity calling itself Zathir as its Speaker.
It's available as an ebook. I can't find a mention of mind-controlling someone through a headset, though.
Found with the Google query
scifi book entity internet site:goodreads.com/book - the title obviously made it stand out as a potential "refrigerator" match.