Is there a prayer for lost objects?

Genesis 21:19.

Midrash Rabbah Genesis 53:14.

The origins of this statement is in the Talmud (Avodah Zarah 18a-b):
Beruria, the wife of Rabbi Meir, was a daughter of R. Chanina ben Teradion. She said to her husband, "It bothers me that my sister sits in the brothel [where she was placed by the Roman regime]." So he took a basketful of coins and set out. "If," thought he, "she has not been subjected to anything wrong, a miracle will be wrought for her, but if she has committed anything wrong, no miracle will happen to her."
Disguised as a knight, he approached her and said, "Prepare yourself for me."
"The manner of women [menstrual period] is upon me," she replied.
"I am prepared to wait," he said.
"But," said she, "there are here many, many prettier than I am!"
"This proves that she has not committed any wrong," he said to himself. "She no doubt says thus to every comer."
He went to her warder and said, "Hand her over to me."
"I am afraid of the government," he replied.
"Take the basketful of coins." said he. "One half distribute as a bribe, the other half shall be for yourself."
"And what shall I do when these coins are exhausted?' he asked.
"Then," he replied, "say, 'O G‑d of Meir, answer me!' and you will be saved."
"But," said he, "who is assures me that that will be the case?"
"You will see now," he replied.
There were there some man-eating dogs. Rabbi Meir took a clump of earth and threw it at them. As they came to devour him he exclaimed, "O G‑d of Meir answer me!" and they let him alone.
The warder then handed her over to him.
Eventually the matter became known to the government, and the warder was brought to be hanged. As he was taken to the gallows, he exclaimed, "O G‑d of Meir answer me." They took him down and asked him what that meant, and he told them the incident that had happened.
They then engraved Rabbi Meir's likeness on the gates of Rome and proclaimed that anyone seeing a person resembling it should bring him there. One day Rabbi Meir was spotted and was chased. He ran away from them and entered a harlot's house. Others say he happened just then to see food cooked by heathens and he dipped in one finger and then sucked the other. Others again say that Elijah the Prophet appeared to them as a harlot who embraced him. "G‑d forbid," said they, "were this R. Meir, he would not have acted thus!" [and they left him]...