Now as far as I know there shouldn't be any problem using a new bulb with less wattage - it will just consume less.
But after the lamp in my oven recently broke, I replaced it (a 40W bulb with E14 socket) with a 15W one rated for use in ovens. It lasted about two days, started flickering, and then broke.
Before I call the landlord to check if something is wrong with the oven (it's not my kitchen) - is there anything I may have done wrong?
Another thing I have noticed in recent months is that I used to get shocks when touching the metallic sink next to the oven. But that's static electricity caused by dry air - if it were faulty wiring it would be more than just unpleasant I'd guess?