Why would exterior house lights blink?

My parents live in a retirement community in Arizona. Their exterior lights can be turned on, off, or set to blinking to alert people of a medical emergency within.
This is the only link I could find for such a device without a paywall or annoying ads:
https://e911.ccso.org/?page_id=482

My parents live in a community with a lot of retirees, and there’s one special light switch in the garage that makes the light over the garage door either turn on solid like normal, or flash 2-3 times a second. It’s an oversize toggle switch with a glowing orange light inside so it’s easier to find, and I believe off is the middle/horizontal position, down is on, and up is flashing. Our theory is also that it’s to draw the attention of police/fire/medical responders, because otherwise it’s a pretty dark area and house numbers can be difficult to see.

Thx. But I don’t think that would explain why sometimes one and sometimes both lights blink. Or why this “emergency” would go on for several days.

It is dark now, and the back door light is on and blinking. Which suggests a solar sensor.

The photo cell uses a different method to detect, but contains a lot of the same circuitry as motion detect to switch power on. It is that section of circuitry that if old, may not work with lower current draw.
More simply. The photo cell may be catching some of the controlled lighting and getting in a feedback loop. Dark, turn light on, light hits sensor, turn off, it is dark turn on…

This can happen in odd ways. A reflective surface that moves in the breeze. Only when wet surface reflects. Leaves or no leaves depending on season.

Two mornings agi, both lights were flashing very quickly - at least 2-3x/second. But not exactly in sync. One was a tad quicker than the other. This morning, one light was not blinking, but the other was blinking more slowly than the day before. I think this morning was likely a little colder than yesterday if that matters - maybe mid teens compared to mid-20s.

Those of you with explanations, would they explain this sort of variability?

Temperature can change the resistance values in components. Consumer components are seldom high precision ones. So there would be a difference in how they perform if they reach the fuzzy edge of proper function. One blinking faster than the other. It may indicate that they are not blinking due to a single controller malfunctioning. But that is not positive.

Ask Kenneth.