Neither Linda nor Graham has yet been identified but dozens of people have spotted the posters around the town, and shared pictures of them to social media.
The laminated messages have been attached with cable ties to lampposts across Warwick, at locations including in parks, at pedestrian crossings, and beneath road signs.
Sharing a picture of one of the posters, Stephen Turner wrote: "Don't think Graham in Warwick will be having a very good day."
Don't think Graham in Warwick will be having a very good day.
Posted by Stephen Turner on Saturday, 7 January 2017
Posting another picture of one of the signs in a different location, Mark Hebert said: "Posters all over Warwick. Naughty Graham."
Posters all over Warwick . Naughty Graham
Posted by Mark Hebert on Saturday, 7 January 2017
Andrew Robins also tweeted a picture of one of Linda's posters, writing: "Saw these all over Warwick today. I think Graham might be in trouble #naughtyboy #womanscorned"
And Helena Wallis posted a picture to Facebook writing: "This made me smile!! What a brilliant poster! All over Warwick - whoever you are Graham - you've been named and shamed!! #revengeissweet".
This made me smile!! What a brilliant poster! All over Warwick - whoever you are Graham - you've been named and shamed!! #revengeissweet
Posted by Helena Wallis on Saturday, 7 January 2017
Sharing yet another picture Alison Tonkin wrote: "Well there's a Graham in Warwick who's having a much worse day than me. Go Linda. #womanscorned #naughtyboy".
And Ben Chamberlain said: "These are all over Warwick. Graham, I don't think Linda is best pleased. Hell hath no fury etc..." as he also shared a snap of one of Linda's signs.
These are all over Warwick. Graham, I don't think Linda is best pleased. Hell hath no fury etc...
Posted by Ben Chamberlain on Saturday, 7 January 2017
Although some social media users were quick to point that Linda could have broken the law by maxing Graham's credit cards and throwing away his keys, others commended her actions.
Jeanette Mason commented on one of the pictures, writing: "So funny. Most of us wouldn't have the nouse or the nerve. Good on ya girl."
And Julie Dingley said: "Well done Linda. Who needs a cheat as a partner!"
The professional-looking posters were erected by a company called Throwing Rocks, which offers a service placing "50 high quality poster boards in a location specified by you."
Although some have suggested Linda's revenge may be an publicity stunt, on Twitter the company was adamant the posters were genuine, saying their website had been included at the bottom as a "way of letting you know who provided the service."