1978 intermittent stall

it had no spark when I put a spark tester on, a few minutes later it started and runs fine.
this has happened several months ago. is their a way to test the spark control module.

The ignition(spark) control module would have to be tested when it was(the vehicle) in a no start condition. Given the history of this vintage Fords, my first guess would be the ignition control module. You may have to go trial and error to solve the problem. Yes, I know, a bit costly beings there is no return on electrical parts.

back in the days of these eletronic spark moduel it was not uncommon to carry a spare they were prone to just stop working i have seen freind bolt a spare right next to the other one

I've owned and driven various old Fords with this kind of module for many years and never had a problem.
I have had a problem with bad ignition coils on several vehicles, including Fords, that intermittently cease to produce a spark, usually as the engine has been running for a few minutes. They cease to work for a while, then will run just fine after they cool down.