Came across this on the interwebs. A supposed Ham being helpful by telling someone with a new HDTV that his interference is being caused by - another Ham. If it's HDTV, then it's very unlikely that a Ham is causing the TVI. Doesn't stop Einstein though...

[iO] HD Channels flicker on and off

I have new 8300HD. Sometimes the HD channels (all the HD channels, but not the regular channels) flicker- the picture and sound keeps jumping on and off for a couple of minutes, then they become stable. Does this sound like equipment failure or something wrong with signal. Any suggestions?
It could be RF interference. Do you have any Amateur Radio operators nearby?

That looks like typical CW (Morse Code) interference, if it was a hum it could be a grounding issue or SSB (Phone/Voice) RF interference. Just an idea... I know when I key up my transmitters it happened until I installed highpass filters on the TV.

Then Mr Helpful posts the name callsign and address of every ham in this guys zipcode - Edited out here.
What is the inevitable response?

What are those names and addresses you gave, because one is only two townhouses away?
Bingo... Those are licensed Amateur Radio operators in Mount Kisco, NY... They are FCC licensed to operate up to 1500 watts on the HF, VHF and UHF bands (frequencies). I am a AR Operator and I had the same exact problem you are having, so I recommend you get a high pass filter and see if that fixes the problem. If it does, it is likely it might be coming from that radio operator when he uses CW (Morse Code).

Morse code is the opening and closing of a circuit, on and off transmissions. It can mess with TVs in close proximity.

Of course, I don't know if that is the problem, but it doesn't hurt to gather some info. Does this happen 24X7? Or is it on and off for a few minutes then stops ofr a while? Does it happen constantly all day and night? If not, then it could be man made.

Also, a lot of AR Operators who live in Townhouses use "stealth" wire antennas, which often means they have inferior grounding (which leads to issues like you're having).

Mr. Helpful then gives the QRZ web address and the FCC ULS Database Addy
He then advises him to install a high pass filter but a few posts later:

It turns out it is not my neighbor. I just spoke to them. They havne't used the ham radio since they moved here over 5 years ago, it is still in the box unpacked. So I guess it is the DVR or the cable. Unless, the addresses on Foxwood Circle are about 2 blocks or more away, could it be them?
Now this is turning into a witchhunt.

Wonder why you have so many problems? It's guys like Mr. Helpful here.

BTW, Mr. Helpful describes himself as "Proud Libertarian Conservative." With friends like this, who needs enemies.

Wonderful guy.

LINK HERE.