This is some background on these devices from wikipedia:

A Tesla coil is an electrical resonant transformer circuit invented by Nikola Tesla around 1891.^[1] It is used to produce high-voltage, low-current, highfrequencyalternating-current electricity.^{[2][3][4][5][6][7][8]} Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits.

Tesla coil circuits were used commercially in sparkgap radio transmitters for wireless telegraphy until the 1920s,^{[1][9][10][11][12][13]} and in medical equipment such as electrotherapy and violet ray devices. Today their main use is for entertainment and educational displays, although small coils are still used today as leak detectors for high vacuum systems.^[8]

Kudos to these brave gentlemen and don’t try this without the supervision of a professional!