Well, there are manyways to start electric warfare, i could teach you how to cause cancer and kill anyone that lives around you without breaking a sweat, but that would be very wrong, and could also kill you...
So, there are some basic ways to do it.
1- Build a huge coil, like the ones used to do ELF recepcion, and build an strong transistor (for low frequency mosfets are suitable too) driver circuit to make the coil oscilate at your disered frequency. Ex... 50Hz or 60Hz...
2- Make an electric line pulse injector, this would affect your devices and some around your house, just inject pulses of very high voltage on the powerline, but this one can be dangerous. If the devices around you are built without any noise supression you can take them down.
3- To cause interference in the TV, well, any coil oscilating at low frequencies will cause noise on the tv, unless it is an LCD or better...
4- Make a tesla coil and use it !
Remember that, it is always easier to destroy than to build something, having this in mind choose carefully your path.
This can be seen as an test to the electronic interfearence resistance on the devices, but if you have anyone with a pacemaker around dont do this, the pacemakers have some protections, but even so, avoid doing this many times. Also, stopping a pacemaker doesn't mean that you will kill the user but you could cause it to go under cardiac arrest, you could make a lifetime change, starting to wake up watching the sun in stripes (yep, in the jail !!!).