PHOENIX -- Having a home alarm system gives Tiffany Elias some peace of mind.
"We set the alarm leaving, when we come and go," she said.
Not long ago in her quiet Phoenix neighborhood, Elias answered a knock from a man at her front door.
"He claimed to be with my current security system and he was changing out the old boxes for new boxes," Elias said.
That seemed a bit odd to her since she never made an appointment with her current alarm company, Safeguard.
"I asked him for his business card," she said. "He would not give it to me because he said I wasn't a customer even though I was."
The man didn't have identification and Elias said a company car was nowhere in sight.
"He was persistent, he wanted to come inside," she said.
Elias did the right thing and closed the door.
"It was really scary," she said. "So I immediately called Safeguard afterwards. They said, 'That was absolutely not us.'"
Elias was likely to become the victim of what's called the door-to-door alarm scam. It works when unscrupulous alarm companies show up unannounced, tell you they're with your current alarm provider and then install their equipment instead. The result? Consumers are contractually stuck paying two monthly bills.
It’s prevalent enough that an advisory from the Arizona Alarm Association was recently issued.
"We'll never send someone to your house unless you have an appointment," said Travis Moss, who is with the company that installed Elias' original system. He said in Arizona all alarm companies and their agents must be certified.
Also, keep in mind that legitimate home alarm installers wear company shirts, travel in marked vehicles and have state-issued IDs.
"If you are registered and you have proper licensing, you'll get a card that has your name, the business that you work for and that means that you've been fingerprinted, you've been background checked," Moss said.
Keeping those things in mind can help protect consumers like Elias. And although her dog is also a great deterrent, she realizes you can't just trust someone who, out of the blue, shows up on your doorstep.
"Nowadays your radar has to always be up," she said. "I think unfortunately there's a level of trust that's just not there anymore."