Have you noticed the bright yellow signs all over the place with "WE BUY HOUSES... CASH!"? Or maybe you have received a handwritten note on yellow note pad with a request to buy your house. I just got one of those at my own house.
Have you considered calling on one of the notices? Here's a great article that will explain what you can really expect:
There's a famous saying "If something looks to good to be true- it probably is!" This is one of those cases.