From ground-based photometric observations made near Dunedin, New Zealand, at L=2.71, weak mid-latitude electron precipitation is detected through the appearance of a characteristic signature in the cross correlogram of &lgr;3914 and &lgr;5577 brightness fluctuations. The method is sufficiently sensitive to detect rms brightness fluctuations at 3914 ¿, &sgr; (Bv), as low as 0.03 R in an observing time of several minutes. During magnetically quiet periods with Kp?3 we observe that &sgr; (Bv), on a time scale of seconds, falls below this limit, which corresponds to a precipitating electron flux of ~200 el cm-2 s-1 sr-1 at 40 keV providing &sgr; (Bv) ~ (Bv). For Kp?5, there is an approximate increase of 5.6 in flux magnitude per unit Kp.