As a source of light, beacons take on the symbolism of illuminating the way to spiritual enlightenment and to sanctuary for the spirit. Our emotions may be 'flaring up' and need directness of communication. If the flame is unprotected a beacon may signify passion. This can show, variously, as a warning, the need for communication or a strongly held principle by which you live. In a mans dream, without the spiritual connotations, a beacon can be a symbol for exuality. In a womans dream it is more likely to suggest passionate feelings. You might like to consult the entries for Fire, Light and Torch.
Dream caution: you are threatened, be most attentive!