Some historians have reported that Edmond Berger invented an early spark plug on February 2, 1839. However, Edmond Berger did not patent his invention. Spark plugs are used in internal combustion engines and in 1839 these engines were in the early days of experimentation. Therefore, Edmund Berger's spark plug if it did exist would have had to have been very experimental in nature.
According to Britannica a spark plug or sparking plug is, "a device that fits into the cylinder head of an internal-combustion engine and carries two electrodes separated by an air gap, across which current from a high-tension ignition system discharges, to form a spark for igniting the fuel."