How to know if a House/Owner is undergoing preforeclosure

[Curtis Daniels]

I was driving past a house today in area where foreclosures are abundant. The house was nice but I could tell by what I saw in the inside of it that the owner may be calling it quits soon. I may be wrong about this assumption, which is why i don't know if I want to call the owner or send them a preforeslosure letter stating that I would like to take it off of their hands if they are willing to get rid of it.

Would sending a letter or calling them up about that be insulting to them if they weren't going through foreclosure?