There's a tool on FamilySearch called "View My Relationship." You can access it on any person's main page, located about the center-top, just underneath their name and ID number.
If you click on it, you'll get one of two answers. You may get a pop up window that says "we can't find a relationship within 15 generations or you are not related to this person." This might be true, or, it's possible that no one has linked the two people together. For example, if I enter my deceased parent as an individual and don't link him to his parents, and his grandparents etc etc., there's no way for the system to know we are "related."
Most likely you're going to flip out to find the person you think is a random stranger is actually your 8th or 9th generation cousin, meaning, you share a common great grandparent, X generations back. It will also show you if you tie in via marriage.
I helped a few people at work these past few weeks do some family history. As a lark, since I was also showing them how to use FamilySearch, I hit the "View My Relationship" button, something I'd never done before. I was shocked to discover Kay and my ex were cousins (making us technically cousins-in-law), that Randall and my ex were cousins, and that I was his cousin via his mother's line, and I was also his wife's cousin.
I was flabbergasted to uncover my former boss (the job I had to quit because the guy was a jerk) and I are 10th cousins.
Or finding out that my adopted (and deceased) daughter and I are 9th cousins through her bio-Mom's line.
The biggest amazement of all involves my DD20. She was walking through a random cemetery one day and "heard" the name Cassie Murphy. No gravestone with that name, just "heard" the name, over and over, along with "her daughter Mamie." So she called me to ask 'how to do genealogy.' Kind of a big question, but with some detective work in census records, birth and marriage records, were actually able to find "the" Cassie Murphy she had felt impressed to find. Along with Cassie's husband Felix Lane, and her daughter Mamie.
Just completely random folk, right?
Out of curiosity, I tapped the View My Relationship button.
You could have knocked me over with a feather to see that Felix and I are 8th cousins on my mother's side, and Cassie, a cousin in law by marriage to Felix.
That's spooky even for me, and I'm accustomed to genealogy spooky.
It brings a whole new awesome meaning to the phrase "blessings to me and my posterity" (Gen. 17:7, Gen. 22:18 and (for those who are LDS remarks by Heber C. Kimball.))
It's starting to get anti-climactic. Now, I'm just expecting to find that I'm related to you, somehow. Like my BFF Wendi. I am of course not surprised anymore, to find out we are 6th cousins (ok, technically, my mother and her are, I'm therefore 6th cousin 1 generation down (called removed.))
It will be exciting for me to find out I'm related to you! So you should contact me and we'll find out!? And no, even if we find out we're related, you're not off the hook for doing your own family research! <grin>
