"unlike someone" is correct and usable in written English.
You can use it to compare one person or thing to another. For example, "Her ambition was unmatched, unlike someone like me who didn't know what to do with their life."
"Unlike someone like Emmeline Pankhurst, it's more difficult to slot Austen politically.
It was unlike someone growing up in LA where everybody's parents were in the business.
Unlike someone who is crippled and can never walk, I can talk fluently when I'm all by myself.
That discovery seemed to temper Nixon's nerves, making her mindful that, unlike someone undergoing chemotherapy, she still had her eyebrows, eyelashes and radiant pink cheeks.
"They have an idealised boy-next-door appeal, and girls feel they could meet somebody like that – unlike someone like Arnold Schwarzenegger or Sylvester Stallone.
But fire investigators, moving slowly through the ruined house, began seeing things (not unlike someone viewing a Rorschach pattern) that they interpreted as evidence of arson.
Perhaps it's almost too personal a project: in fact, listening to Freetown Sound feels not unlike reading someone's diary.
The vocal tract physically differs from one person to another, but unlike verifying someone's identity through fingerprints, voice recognition is indirect.
This is not unlike selling someone a wristwatch that requires a pocket watch to work".Wearable computing", a category of technology that includes small watches, fitness trackers, glasses, jewellery and clothing with sensors, is an area of great promise, but has so far been limited to communities of geeks and fitness buffs.
Unlike losing someone to a physical death, with divorce you're left to grieve alone.
Unlike, say, someone with the name of "George," you pay attention to how words are pronounced and their correct usage.
