Use what formula ?



I want to buy some capacitor for arc suppression for my table lamp (
12 Volt bulb ) . I
am not sure what value to use, for eq, 0.22 uf, 0.1 uf or 0.01uf . I
would like to know
is there any formula to calculat the actual value. Does any one know
of a formula ?
Thanks for help.

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