Breaker Tripping Question

I have a 20A breaker that appears to only have 1 outdoor dusk to dawn light (comes on at night, off during day using a sensor.

All the sudden the breaker tripped a while ago and the light no longer worked. The breaker wasnt fully off, it was kind of in the middle, you could wiggle it a bit. I turned it fully off then back on and the light worked. 4 days later and the breaker tripped again.

What can I check for or is this something I need an electrician for no matter what? Like I said, its one line that appears to use that 20A breaker as nothing else is off / doesnt work with it off

As you can see from my incredibly well described issue above, Im not an electrician. I can change a light socket, I can install a ceiling fan, I can wire up led lights...thats about where my expertise ends!!

Any help is greatly appreciated...