Is this a scam? I was hired to work for an investor using quitclaim deeds

[Karen Closkey]

I saw an ad on Craigslist that they need someone to do private investigator type work. I answered and the person told me they work for private investors. They are trying to get ahold of a homeowner to buy his second house which is in foreclosure. I would get $400 once the homeowner signs a quitclaim deed and 0 if he does not proceed. 

Could this be a scam of some kind? Not only am I worried I won’t get paid because I have no contract with the investors but I don’t want to be a party to a scam to hurt the homeowner. I have to say I work for the investor, not that I am a process server or courier. I am not a realtor or lawyer. I am concerned the check could be fake or the homeowner never gets paid. What should I do? I have a phone number and name of a lady and email but she said the investors don’t have a company name.