I'm not convinced that your example proves your claim. The problem is perhaps more likely related to interference at the radio's intermediate frequency rather than a switching frequency at or near the FM broadcast or TV channel frequency.
Well, I didn't fill out all the details, sorry about that. Here they are:
I installed a 50ft high antenna system on my house. That consisted of separate VHF and UHF antennas, a pre-amp, quad-shield cable and such. The VHF antenna is aimed at the single VHF station in my DMA (that I wanted), WJRT channel 12. ALL the rest of my channels are UHF.
Anyway, I was having interference issues on VHF 12, and spent a lot of time tracking them down. Once somebody mentioned "switching battery chargers" to me, I started thinking about this. They said it could be tracked down using a radio. I then noticed the car radio interference, since that was my easiest radio to access. I then remembered that I had a charger plugged in in my garage, tending a deep-cycle battery. Once I unplugged it, the interference stopped.
A couple days later, new interference about almost the same, started up. That turned out to be my Dell laptop power brick. I replaced it, and that interference went away to never return.