Lawn Mower (probably) Electrical Problem
So, I found what it was.  The plug was OK, and I laid it on the engine block and cranked the mower to verify a spark.  It had a spark so I figured it was fuel.

I took off the air filter cover and the 2 bolts that hold the air filter housing on the carb and removed the housing.  On the float bowl of the carb there was a wire coming off and going to a jumper that was not connected.  The other end of the jumper went to ground.  When I hooked this back up (i.e. re-connected the wire via the jumpers), it worked like new.

I have no idea what that is, maybe something that helps atomize the fuel, or a fuel pump relay?

Dunno, but it was electrical, just not a safety switch like I thought.