Looking for ideas on this.

Porch steps have wired lighted caps that come on a couple hours at night. The porch is also lit with in-ceiling cans on a separate switch.

Looking for a small fairly inconspicuous IR beam type of sensor, placed at the lower step behind the post, that is wired to a relay so when someone starts up the steps beyond the lit hours, can (via programming) kick the lights on for a short time.

Garage door sensors? They're designed to be in the cold, don't know about wet though.

[Link: surveillance-video.com]

[Link: zoro.com]

[Link: smarthome.com]

[Link: northshorecommercialdoor.com]

Why not just install LED lights that come on at dusk? They use so little power and take no maintenance. I put one on my (indoor) stairwell a year or so ago. I think it's 1 watt power consumption, but super bright.

Go to Amazon and search stairway LED lights.

There’s a cool factor for sure and if you can why not?

It's an outdoor stairway. About 5 steps in total that lead to a porch. The porch is already lit hardwired with 12v lights. Those lights as well as the can's are on timers. Safety/security reasons are the driving forces here. Think of it as a trip wire motion sensor. I googled around a bit and found solutions that may have potential via the manufacturing/packing automation industry.