MIRANDA LAMBERT’s got a mes­sage for her flirtatious hubby BLAKE SHELTON: Keep away from CASSADEE!

Blake mentored gorgeous 23-year-old Florida native Cassadee Pope on Season 3 of “The Voice” – and Cassadee went on to win the hit NBC singing competition. But Miranda is terrified that the professional relationship between Blake and the beautiful up-and-comer is getting a little too chummy – and sources say she lashed out at Blake in a jealous rage recently.

If history is any indication, Miranda, 29, has plenty of reason to worry – her romance with the “Honey Bee” singer started when he was married to another woman!

According to a source, the blowup took place after Blake gushed – again – about Cassadee’s spectacular win.

“Miranda finally had enough,” the source explained. “She exploded with wild jeal­ousy. Miranda is afraid that Blake will fall for Cassadee the same way he fell for her.

“She finally laid down the law and told Blake to keep away from Cas­sadee – or else!”

Blake’s ex-wife, Kaynette Williams, listed his “inappropriate marital conduct” as the reason for their split in divorce papers filed in 2006.

Blake, 36, has even admitted that he fell for Miranda while he was still married. Cupid struck him when they first performed together onstage at CMT’s 100 Greatest Duets television special in 2005. And they tied the knot six years later.

“Blake is her whole world and she’d rather die than lose him to another woman,” the source added. “Miranda’s watching Cassadee’s every move, and she’ll have no problem baring her claws if Cassadee gets too close to her man.”