ASHTON KUTCHER’s pole keeps getting him in trouble – his fishing pole, that is!

The “Two and a Half Men” star, an avid fly fisherman, annoyed co-star JON CRYER when he kept bringing his rod and reel to the set to sharpen his technique – casting at objects on a table 40 feet away as he prepped for an upcoming piscatorial adventure with MILA KUNIS.

Hooting in triumph as he reeled in scripts, hats, scarves, magazines, etc., Ashton “damn near snagged Jon Cryer, who’d walked over to the table to pick up his own script,” said a source.

“Jon snapped, ‘You’re really gonna hurt someone one of these days!’”

Next morning, Ashton entered his dressing room, smelled a strong odor, looked up – and saw a 4-foot long salmon dangling from a hanger. Attached was a note: “Here’s your big salmon – now put your pole away!” It wasn’t signed, but Ashton – who’s no crier and instantly cracked up – has his suspicions!