Your problem is much more apt to be a poor connection at the spark plug or a break in the spark plug shielding than to be the kill switch. Of course removing the kill switch for trouble shooting will cost you nothing but time so it will not hurt to check that out. You might also check to see if there is some metal to metal connection that has become loose and is vibrating or some insulation or touching wires have become frayed and now intermittently touching when the engine is running and vibrating. Most probable cause is spark plug wire or shield followed by some metal to metal contact that is now occuring. What ever you find, please pass on to us what the solution was for our education.