Identify a light emitting component
It's a neon light. Like it says it works at the mains voltage, you can't make it work at 5 V or so. The thing with the neon light is that it needs a higher voltage to ignite, but then the voltage drops, and the series resistor then will control the current, just like for a LED. So you need the resistor, which may have a high value, like 100 k&Omega; IIRC. Then the current will be in the order of 1 mA.