Jesus gives instruction not to go if anyone says there he is, because ...
For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be.
Matthew 24:27 KJV
So it is further clarified in the letter to the Thessalonians.
For the Lord Himself will descend from heaven with a shout, with the voice of the archangel and with the trumpet of God, and the dead in Christ will rise first. Then we who are alive and remain will be caught up together with them in the clouds to meet the Lord in the air, and so we shall always be with the Lord.
1 Thessalonians 4:16-17 NASB
So we don't have to worry about which claimant is the real deal, because when he comes it will be no big secret, and he will gather us to him.