No Crank, No Start, Clicking under dash

[BAKeefe4]

I have a 2009 Ford Fusion SEL, that sometimes it will start fine and other times it will not. sometimes it can be after sitting all night and other times after sitting for 30 minutes or so. it will go days starting just fine then out of the blue it will not. when I try to start the car during the times that it don't want to start I hear a click under the dash drivers side. I watched some videos and read some articles and it sounded to point to a worn ignition switch (key Switch) so I held the key over in the start position and could hear a repeated click under the driver side dash that was steady and rhythmic. the first few times that this no start happened it started on the 3rd click now it is happening more often and taking long before the start if at all it does now. Before anything said, New battery cleaned both ends of the cables checked the solenoid. Just haven't changed the battery in the key fob. I do not get the security light but does come on during the self test. I need help as this one has me baffled.