Albert Barnes on Acts 16:29

Then he called for a light. Greek, Lights, in the plural. Probably several torches were brought by his attendants.

And came trembling. Alarmed at the earthquake, and amazed that the prisoners were still there, and probably not a little confounded at the calmness of Paul and Silas, and overwhelmed at the proof of the presence of God. Comp. Jer 5:22, "Fear ye not me, saith the Lord? will ye not tremble at my presence?" etc.

And fell down, etc. This was an act of profound reverence. Mt 2:11. It is evident that he regarded them as the favourites of God, and was constrained to recognize them in their character as religious teachers.

(d) "and fell down before Paul" Jer 5:22