For an electrical and electronic engineer or hobbyist, AliExpress today has this
Digital Electrical Multi-sensor AC/DC 12-220V Test Pen With Night Vision NG4S US $1.83 + Free S/H. I just placed an order of 2x and paid using a smartphone US $1.81 (total US $3.62) + Free S/H. No and this test pen does not have a night vision, but rather an LED driven by the electrical power when the tip of the test pen touches a hot (live) wire. Internally, it may have some built-in capacitors to temporarily store a limited power to light up the LED.