Occasionally I will get returned mail with "invalid address" even though the owner address matches the county record.My next step is to use USPS's address verification to see if they will make any corrections to the address so I can re-send it.If that fails I will do a google search for the owner name to find alternate contact methods (linkedin, facebook, maybe an address)And lastly there is a skip tracing service called TLO by TransUnion that I have heard discussed a lot but I haven't tried myself, yet.Why this happens is a mystery to me!

To be fair, I did receive a decent amount of money for the reno but as we opened those "mystery walls" things got pricier.  

@ Joseph M - it was a $400k SFH in Tempe AZ.... so not your typical OOS C- rental....mine was renting $1600 back in 2004...Still tenant don't seem to stay more than 6-9 months , non stop repair request, all repairs at 3x the price.... on and on and on...This is still a mystery to me... when I self managed my rental in SF, tenant stay 3 to 7 years, 1 repair a year if that much....To this date, I did not figure out why OOS rental is non stop issues for me..At any rate, that property, had I hold it, rents $1800 today and about $340k today.... so good decision I did to cut loss... pad on my shoulder ...lol

How he paid it off is a mystery, at least in theory, but the bank suspects he may have fraudulently obtained a joint loan in his ex-wife's name.

The universe works in mysterious ways. 

The universe works in mysterious ways.

Another weirdness that you may or may not face...many of the homes were continually having big wet spots appear in/on the slabs, hundreds of people, were calling leak detection services, thinking an underground plumbing leak was causing these mystery wet spots.

@Phillip Lanier  The mystery scraper is..........................ME!

The mystery of the disappearing lien is I believe solved somewhere in that transaction.

i think the biggest mystery how can someone have 17k posts and 17k votes 100%   @Jay Hinrichs