Many people glorify the miracle by lighting Ĥanuka candles wherever people gather, like at weddings, bar mitzvas, bat mitzvas, Ĥanuka parties, and lectures. But may one recite a berakha over the lighting at such an event? Many contemporary rabbis maintain that one should not recite a berakha, because the berakhot are customarily recited only in synagogues, and we do not have the authority to invent new customs in other places. According to them, a berakha that one recites in places other than a synagogue is considered a berakha le-vatala. The reason we light specifically in synagogues is likely to commemorate the Menora that was lit in the Holy Temple, since synagogues are considered miniature versions of the Temple. Elsewhere, however, one may not light with a berakha. Nevertheless, several poskim maintain that one may light Ĥanuka candles with a berakha wherever there is a public gathering. Since the reason we light in the synagogue is to publicize the miracle, one should light with a berakha wherever masses of people gather. It is preferable, though, to pray Minĥa and Ma’ariv – or even just Ma’ariv – in such a place, so that it will be considered a synagogue, to some degree. Then one certainly may recite a berakha, as the custom dictates.
In practice, one who wishes to rely on the opinion that one may light with a berakha may do so. If the guests at the event include non-observant Jews, who may not have lit candles at home, it is especially important to light with a berakha, because only then will everyone stand up – to hear the berakhot – causing the miracle to be publicized in front of their eyes. They will also learn how to fulfill the mitzva properly. If possible, it is preferable to ask someone who is unaccustomed to performing mitzvot to recite the berakhot and light the candles. This way, it will become clear that the mitzvot belong to the entire Jewish people, observant Jews and non-observant Jews alike.
The reason I wrote in the main text that it is preferable to ask a non-observant Jew to light the candles is that even if the halakha follows the more stringent opinion, we can view his berakha as educational, similar to our practice of training minors to recite berakhot.