my calculator says.... 300VDC (after being rectified from 240vac)
R1 = 13k
R2 = 680 ohms
Voltage out 4.5volts (from 300vdc) using a voltage divider, the resistive load is 280ohms, what ever that equates to in amps, 4.5/280 = 0.0160 amps
/ 0.0723 watts.
How's that sound? - but again, i still would not do it even if you told me it was safe 