If it's a house with lots of pictures, especially if the price seems really good, do an image search and see if the house was recently listed for sale on a real estate site.

I nearly got scammed by two of these when I moved here three years ago... The scammers took pics from houses that had recently been sold, then listed them on Craigslist for rent.

I found a bunch of other fake listings once I realized what was up. The scammers aren't even local - one wanted me to send money to a residential address in Houston, TX. I can only imagine this has gotten worse in the last couple years.