At a theoretical level, RF interference and 60hz hum are the same source of noise.
Yes everything from above DC to light is part of what is called the Electro-magnetic spectrum.
But different parts of that spectrum act differently on different devices.
How do pickups work?
They work by magnetically sensing the strings disturbing the pickup's magnetic field.
What frequencies are pickups most sensitive to?
Well considering that normal tuning for a 5/6 string bass usually starts out at about 30 Hz and with harmonics for the higher pitched guitar it can go up to several thousand Hz. So your pickups are most likely going to be sensitive to the same audio that you can hear. Otherwise what's the point?
RF or RFI is a specialized range of the electromagnetic spectrum.
Technically the RF part of the elctro-magnetic spectrum starts at 30 KHz (30,000 cycles).
A bass/guitar pickup is not very sensitive to these frequencies.
However, it is possible that an electronics device will receive and respond to unwanted RF frequencies.
There is a whole section of FCC regulations devoted to this. It's known as part 15 of the FCC rules.
But RF (RFI) getting into a bass amp will not produce a 60 Hz hum.
It most likely will be hiss, unless there is diode action going on due to a corroded connection demodulating an AM (Amplitude Modulation) signal.
Because of the insensitivity to RF, an RF signal will have to be many magnitudes more than what your bass pickups respond to.
You bass is just about as likely to respond directly to radio frequencies as a radio receiver would respond to light.
A near by, high powered AM radio station broadcasting a 60 Hz signal for it's programming could be detected by your instrument if there was a problem with the instrument that caused it to act like an AM detector. That would produce hum in your bass by RFI. But what are the chances of your local talk-radio station playing hum as programming?
In the home, anything that runs on a power source, DC or AC, batteries, solar, wind, generator, power grid is a potential source of interference, be it EMI or RFI. The trick is to find out what that source is, why it is causing a problem, and then what do you do about it. You can remove the source of the interference or you can take measures to make your instrument less sensitive to the interference without affecting the frequencies of interest. But not finding the source may mean that each instrument will need to be treated. If you can mitigate the problem at its source, that, IMO is the best solution.
