1988 Dodge Dynasty Intermittent Starting Problem

Background info:
About 2 months ago all of the electronics stopped working and the car died while driving, this was an alternator issue and I had it replaced which resolved that problem.

A few weeks later I was driving the car, stopped at a resturant, came back an hour or so later and the car would not start. It would make a clicking noise. All of the electronics worked (headlights, radio, brake lights). I had it towed to a machanic who said they couldn't find anything wrong with it, at that time it was starting fine, they said the battery was good they charged and cleaned it and so was the alternator, and starter. They said when it happens again, tap the starter with a hammer to see if thats the culprit or have it towed back so they can have another look at it.

Now a month later on my way to work the "check gages" light turns on. So once I get to work I turn the car off, then try and start it again and hear a click noise then hear nothing and it won't start. I come back 2 1/2 hours later and it starts up fine, I try and start it another 2 hours later and it starts up. Any idea of what might be going on?