My 1998 VW new beelte was shaking when i start it up, when damp....i bought new

[SAUCER_99]

spark plug wires but it still? shakes when damp. I thought it was the spark plug wires. My mechanic suggested i get a new "electronic module"
the problem is i cant find one online or anywhere...is there another name for it? Its located near my spark plugs and wires...its a little rectangular shaped thingy....please help!!!
What part is this and is it possible that this could be the culprit?
Thanks!!

 

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Check out the distributor cap might be where the problem is if it gets damp inside,that will cause the same problem