Whether you're buying a purse, pills, Christmas lights or an extension cord online, make sure it's the real thing or you might regret it.

In an article on counterfeit goods, Consumer Reports noted, "As the world has grown smaller, more and more foreign-made goods are hitting our shores. Among them, a flood of fakes, fueled in part by the Internet and the ease with which we can buy products directly."

You may be thinking: What’s the big deal if you accidentally buy a knockoff?

“If the product is something that you put in your mouth, like medication, or if it’s something you plug in, you are in danger of injuring yourself or someone in your family,” says John Drengenberg, consumer safety director at UL. For example, counterfeit extension cords may not have as much copper wire in them as UL-tested ones, Drengenberg notes. Because of this, they probably can’t handle the amount of volts or amps for which they're rated. That means they could overheat and start a fire, as shown in this video.

Related: When a Real Deal Turns Out to be Fake

To protect yourself from accidentally ending up with a knockoff, follow these tips.

1. Shop at stores you know and trust, Drengenberg says. It’s unlikely you'll end up with a counterfeit product if you shop at well-known big-box stores. If you’re shopping online at a retailer you don’t know, carefully inspect the website and the product description. “Look for misspellings or bad punctuation,” Drengenberg says. “If you see those, somebody’s just trying to make a quick buck. They may grab your money and disappear.”

To protect yourself from malicious sites that want to infect your computer with a virus, make sure your virus protection software is up to date. And check your credit card statements regularly for any fraudulent charges. Some fake online pharmacies, for example, may fail to protect or even deliberately steal your personal data, according to experts.

2. Avoid products that are most likely to be counterfeit. Drengenberg says these are often high-volume, low-cost items such as smartphone batteries and chargers, extension cords, Christmas light strings and night lights.

Related: A Real Shocker: Knock-Off Phone Chargers Can Hurt You or Worse

3. Check the product when you get it. Look for brand names and words misspelled on the label or packaging. Also watch for phony UL symbols. Labels for certain product categories, including extension cords, now include a gold hologram with embedded codes and color-shifting ink.

If you bought an electric product such as a hair dryer, check that is has a ground-fault circuit-interrupter (GFCI), advises the Consumer Product Safety Commission. GFCIs help protect you from electrical shock. Look for a large, rectangular-shaped plug at the end of the dryer cord.

4. If you already bought a counterfeit product, don’t use it. Return it to the store, Drengenberg says. You can try sending it back to the manufacturer, but you may not hear from them or get your money back. Consider leaving a user review on the website with your experience.

Angela is a Pulitzer Prize-winning digital editor with more than 15 years of experience delivering news and information to audiences worldwide. Prior to joining SafeBee, she was the features editor for Boston.com at The Boston Globe, overseeing health, travel, entertainment, business and lifestyle coverage. Before moving to features, she was the news and homepage editor, covering stories such as the Boston Marathon bombing, Red Sox World Series victories, presidential elections, a papal inauguration, and more. Her favorite safety tip: Clean your phone! The average cell phone has 18 times more germs than the toilet handle in a men’s restroom.