A stranger calls you at home, and your caller ID shows the call is coming from inside your house.
It may sound like a plot from a horror movie, but it's become all too real for some people.
It's happened to several local women and landed two people behind bars.
"The caller would say something along the lines like, 'I'm inside the house, watching you,'" Montgomery County Prosecutor Anthony Gil said.
Danielle Zimmer pleaded guilty to helping to terrorize four Montgomery County women over their cell phones.
Limerick police and prosecutors said Zimmer gave her accomplice, 30-year-old Carmen Veneziale, the victims' cell and home phone numbers to make frightening calls.
"These calls were made at 1 o'clock in the morning or the vicinity of 1 in the morning," Gil said.
Breaking news and the stories that matter to your neighborhood.
Prosecutors said Veneziale would call the victim's cell phones saying "I'm watching you."
The speaker would go on to say "I like watching you sleep."
Limerick police said one victim handed the phone to her father.
And Veneziale said to her father, "I like watching your daughter sleep."
But here's most the frightening part.
Veneziale used technology from a legal Web site. With it, he was able to call his victims' cell phones, but make their own home phone numbers show up in the cell phones' caller ID, making it appear as though the caller was hiding inside their homes.
Police said the calls were in April of last year.
Limerick police said within a few days, they tracked the calls to Spoof Card.
Investigators said Spoof Card cooperated, and shortly after, the couple was arrested. Both recently pleaded guilty to terrorist threats and harassment.
Spoof Card's Web site says, if used illegally, they will cooperate with the law.
And prosecutors said they'll make sure you pay the price.
"I can say that the Montgomery County District Attorney's Office takes this seriously and will prosecute to the fullest extent of the law," Gil said.