Light bulbs blowing and crazy wiring..

[Tony Good]

I'm hoping to get a bit of expert advice on a problem I have with a friend's wiring. Initially I was asked to take a look at a three-bulb light fitting that was regularly blowing bulbs. I took the fitting down from the ceiling to check for loose wires and found that several came out from the connectors on gentle manipulation.
I re-prepared the free wire ends (they looked a bit damaged) and inserted them back to where it looked like they came from, disconnected the fitting and checked and cleaned the bulb sockets, looked like some arcing was going on arond the bulb thread.
What's most bizarre on reconnection of the fitting though is when the light is OFF the bulbs glow dimly and when it's switched ON they glow normally. It's part of a two ceiling fitting and two way switch circuit with ordinary 40w filament bulbs.
Looking at the back of the wall switch it looks like the two circuits are crossed between the switches - I just can't understand why it was wired like this and wondered if it sounds like a familiar, albeit odd, setup to anybody?
Would welcome any sensible input.

 

[HandySparks]

If 40W filament bulbs are glowing when they should be off, there's something significantly wrong. You need to get this checked out properly.

(If they were LED lamps, then there may be nothing to worry about.)

 

[GMES]

Tony I am closing this thread as it is identical to the other one you started, can you create one thread please mate so we don't have members flitting round the forum answering the same questions twice.
Cheers GMES