Intruder discovered on my bandwidth

if you have not taken the correct safeguards ... yes

Easily - if you have not secured your network.

Guy

Thanks for the replies and for setting my mind at ease!

I had assumed security had been implemented at installation. Maybe it had not however.

stefos

Not only is the answer "yes" as others have pointed out, but in many cases it's the default action when you first turn on the wireless interface: it just grabs the strongest wireless signal it finds. If he has his own wireless AP, and has done nothing to secure it either, the odds are fairly good that his computer can't even tell the difference between his AP and yours (eg, if they both come from Linksys, they're called "LINKSYS" by default, and they require no security keys - even the administrator passwords are the same: which could cause havoc for you if he decided to change his by wireless!).

In addition to the answers that you have already received why not just answer the following questions to yourself.

"What must I do in order to connect to my wireless network, what security information must I offer?"

However just because you believe you have secured your network does not make it so but then that's the difference between someone inadvertently connecting to your network and deliberately defeating security provisions in order to do so.

David.