I presently have 4 power bars with flickering neons, 2 are out, and 4 are OK. These are in the illuminated rocker switch.
A bushel of small neon lamps (w/resistor) from
Ali $0.08 ea. shipping included. A replacement illuminated rocker switch is $1.00
Once I swapped over to a 3mm LED inside the switch but it was gross because the leads are part of the switch and very cramped in there, but it works fine.
I have NOS quality green neon panel indicators, UL/CSA approved snap-in IDI going for $13.50 at DK/Mouser now. Unbelievable.
Next I got some LED mains indicator lamps on Ali
DIANQI Store $0.80 but these have no safety approvals for the insulation to the metal housing. I took one apart and there is a reasonable sleeve design but susceptible to sloppy manufacturing at the soldered wires. Inside it's a double-die 3mm red LED plus 68k 1/8W resistor (110VAC version).
LED power indicators I did 17 years ago, today are fine at 150,000hrs (1/2 wave so 75,000hrs) InGaN, 25VAC, 1N4007, 4.7kΩ, 3.5mA RMS, 7mApk.