The stray flashes of faint light on LEDs is induced current from the lamp wires laying along side the solenoid and relay wires within the tightly wrapped wire looms (same electrical principle that makes a transformer function). It is often most noticeable on match and ball lights in the head when you are watching someone else play.
The capacitors that are part of non-ghosting LEDs that helps smooth the pulsating DC for GI, also helps the led not light immediately with the quick pulses of power.
So super cheap LEDs which are nothing more than an led and current limiting resistor will obviously flash 60 times a second. Causing the strobe light effect as you eyes track the ball in motion.
AC/DC type that have a bridge distinctly flash 120 times a second. Which many humans may not notice.
Premium non-ghosting tend to not flash as much due to the added capacitor which may or may not, completely eliminate the 120 pulses a second of DC power.