Hi Gemma ,
first of all I would like to apologize for the amount of smart-arsed comments posted on your thread. Electricians has a somewhat bloated self of self importance when it comes to electrickery and also have a tendency to forget just how strange and , at times , terrifying electricity can be to people who have had little or no training in the matter. These people were , more often than not , crappy apprentices who were still getting the brews and butty's in their 3rd year and continued to be treated throughout their miserable lives with no respect due to their bitterness at failing to become plumbers.
ok , so first up , the tester you are using is notoriously unreliable and if you touched must object around the house you would get a similar reading.
The radio frequency detector you are using , would probably , depending on which type of conductive metal you are aiming/in contact with , would trigger anyway as most metals are refractive in their affects on radio frequencies and this tester is simply showing that.
In order to install any kind of secret transceiver or listening device , you would need a power supply and normally these are fitted in specialist light bulbs or sockets.. never(not once... ever) have I seen one fitted in a window. The warm spots you are talking about may simply be that your windows have developed a fracture in the seal and are allowing moisture and air in.
Rest easy , ignore the --- clowns on this thread and don't be afraid or intimidated by your lack of knowledge to post again as most of these bullies will be dreaming of unblocking drains when they should be helping people out.
Plungers at the ready , ladies.
