It's been raining for a few days in the GTA (I see the OP is in Toronto) - therefore the humidity is 100%.
Go buy a can of WD 40 and spray the plug wires and see if that resolves your issue. If so - buy a new set of plug wires and replace them one at a time (one off - one on).
Go buy a can of WD 40 and spray the plug wires and see if that resolves your issue. If so - buy a new set of plug wires and replace them one at a time (one off - one on).