So she applied, and couldn't believe what showed up a week later in the mail: a check for more than $3,000.
"It had the heat resistant marks on it, and It looks like a real cashier's check," she said.
The instructions told her she would be evaluating local banks, earning $350 for her time.
But there was something strange about how she was to be paid. "I was supposed to first keep my check and cash it, and keep the $350," Tull said, "and send the rest of the money to the secret shopper company."
That raised her suspicions. She was supposed to deposit the check into her bank account, then wire transfer most of it into some unknown account.
So Hull Googled the job offer, and soon realized she was about to fall for as a phony check scam, that could cost her thousands of dollars.
Warning signs of a scam
So how do you know if a mystery shopper job is legitimate or a scam?
A legitimate job typically asks you to test out a store or restaurant.
It should never tell you to test a bank or Western Union's Money Gram.
It should never instruct you to buy prepaid gift cards, to test a store's gift card counter.
It should never ask you to deposit an unusually large check in your bank account.
All of these offers involve you cashing a check for $1,000 or more that they send you. But the check will bounce, and you will end up sending your own money to the scammer.
Legitimate mystery shopping jobs
Want to mystery shop? Your best bet is to check with the Mystery Shopping Providers Association at www.mysteryshop.org.
Hull is speaking out because she doesn't want others to get hurt. "That could be somebody's last little bit of money they have, or a single mom struggling, and that could be her last little bit of cash," she said.
Bottom line: no legitimate company will send you a check for several thousand dollars, before you even start your job.
That way you don't waste your money.
“Don't Waste Your Money” is a registered trademark of Scripps Media, Inc. (“Scripps”). John Matarese reports on deals and scams so you Don't Waste Your Money. "Like" his page on Facebook and follow him on Twitter @JohnMatarese.