150830-1559 EDT
chris kennedy:
I believe a 120 V switch is a bad choice for switching low current 5 V DC circuits.
A suitable switch at this voltage level and lower is a reed, a gold plated or cross-bar, a mercury, or solid-state switch.
Most copper based and silver switches develop non-conductive surfaces from atmospheric contamination. I have equipment that I built 55 years ago with 50 millionths gold over nickel contacts that work perfectly today yet HP, Tektronics, and other commericial equipment that used silver contacts from that same time period require much switch turning to make good contact, and sometimes that does not clean up the contacts. Nikel is not porous in thin layers, whereas gold is. Gold has to be 250 millionths or more to prevent base metal under it from migrating thru the gold.
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