Haha I do know that you can open the back of the camera just a little bit and close it again really fast to get light leaks — but I haven't tried it yet and I don't know what the amount of "damage" it actually brings about. All the light leaks I have in my photos were accidental!
I have no idea to be honest! I very rarely get them, so I don't think my camera has a major leak. But maybe there is a smaller one that only has influence on the photos when the back of the camera is in a certain position/not 100% closed?