This is usually a Deacon, who is fully trained and has therefore been granted special 'license' to carry out a recognised Eucharist, if there is no Priest present.
Deacons will always carry the consecrated elements of the Eucharist to the people who are sick or shut ins, etc, in any case, but Deacons ordinary, are unable to preside at a Eucharist Altar proper, without being properly licensed with Holy Orders for this function.