PAWTUCKET — The women said what they did was a prank on the ex-girlfriend of the man one of them is dating. But the two men who saw the ex-girlfriend on the Craigslist Web site didn’t know that. They showed up at her house to answer her ad for sex.

The state police are calling the matter cyberstalking.

On Sept. 10 the state police arrested Trina Young, 23, and Melissa Young, 19, of 618 Cottage St., Pawtucket, for posting sexually explicit material about the ex-girlfriend on Craigslist and MySpace, according to Lt. Steven Lefebvre, patrol commander of the Lincoln Barracks.

The women are scheduled to appear in Sixth District Court today.

Lefebvre said the women allegedly posted a picture of the victim and wrote “looking for a man or woman to share sexual time with.” He said the sisters allegedly posted the woman’s name and address.

On July 24 two men showed up to the woman’s home looking for her. When her sister answered the door they told her they were answering her ad. They told the sister they saw the ad on Craigslist. The sister turned the men away.

The ex-girlfriend, 24, also discovered that the sisters had posted their handiwork on MySpace. That same day she went to the Lincoln state police barracks to report the posting. She told the police that the postings were embarrassing and hurtful to her and caused her to be scared, Lefrebvre said.

Lefebvre said Melissa Young is the current girlfriend of the victim’s former boyfriend.

“Both sisters came in and gave a statement admitting what they did. They claimed they created the profiles as a joke because they did not like the complainant because she was the boyfriend’s ex-girlfriend,” he said. The sisters said the boyfriend did not know about the posting and he was not charged, Lefebvre said.

According to Rhode Island law, whoever transmits any communication by computer to any person or causes any person to be contacted for the sole purpose of harassing that person or his or her family is guilty of a cyberstalking, a misdemeanor. A second conviction of cyberstalking would be considered a felony.

tpina@projo.com