Can other electrical devices play radio sound?

Answer

Yes, that is a phenomenon that you are undoubtedly familiar with. If you place your mobile phone next to your radio, just before the mobile phone starts to ring, you will hear interference on your radio (a kind of rhythmic hum).

There are two reasons for this.
First of all, your radio is very sensitive because it is made to pick up rather weak signals that are broadcast tens of kilometers away. In comparison, the signal strength of a nearby mobile phone is very high (a few orders of magnitude greater).

Secondly, the technology isn’t perfect… If everything worked perfectly, the radio and cellphones wouldn’t interfere with each other, because they work on different frequencies. FM radio typically operates around 100MHz, cell phones at 850 – 900MHz or 1900 – 2100MHz. A radio uses a filter to filter out only the frequency you want to listen to, but this filter is not perfect: it not only lets the desired frequency pass, but also the so-called harmonic frequencies (that are the multiples of the desired frequency, so 200MHz, 300MHz, etc.) is very much attenuated. Your mobile phone also has this problem: it not only emits a signal at the basic frequency, but also (strongly attenuated) secondary signals at the sub-harmonic frequencies (eg 1/2, 1/3, etc. of the basic frequency).

And so it happens that (a harmonic frequency of) a signal from your mobile phone still passes through the filter of your radio receiver and is therefore also converted into sound.