What did Gideon make from the gold earrings, which became a snare to Israel?

Answer: An ephod

Gideon made an ephod and placed it in Ophrah. All Israel worshiped it, and it became a snare to him and his household.

“From all this Gideon made an ephod, which he placed in Ophrah, his hometown. But soon all Israel prostituted themselves by worshiping it there, and it became a snare to Gideon and his household.”— Judges 8:27 (BSB)