Current can cause interference with nervous control, especially over the heart and lungs.
And equipment that makes no use of radio frequencies can also cause interference.
A computer in the same building can cause interference.
The wall has not really disappeared, it is just too thin to cause interference of visible light.
The channel might already be in use on those other towers and could cause interference with existing calls.
The return signal of the tag may still cause interference for other radio users.
In general, the larger the front to back ratio, the less likely the antenna is to cause interference.
Operation of personal radio device that cause interference to other services may result in prosecution.
Unfortunately, the narrator couldn't really do that, because it would cause serious interference with the plot.
"They were keyed to cause interference and attract attention this way."