When a capacitor and a resistor are connected to AC lines, a constant current can be maintained through the resistor, so long as the Rectance of the capacitor is greater than the resistance of the resistor. The current flow depends on the value of the capacitor assuming that the input voltage is greater than the output voltage.
The current through the resistor R is
I RMS = V1 x X C
Where XC is the Rectance
As a rule of thumb, 70 – 75 milli amperes current will be available per uF from an AC capacitor