If the lights (with plastic ceiling disks) and pictures in your Lundby dollhouse keep falling down, you're not alone! Instead of using glue or a permanent adhesive like double-sided foam tape, you may want to try a removable adhesive like Glue Dots. They come in a roll and can be found at most craft stores.
I simply unroll the backing paper and touch the back of the item I want to hang (in this case a Lundby clock) to one of the sticky dots.
The dot is transferred to the back of the clock, which is now ready to hang.
Removable Glue Dots are nice because they won't stain paint or paper, and you can generally peel items off (carefully!) without damage when you want to redecorate.
Another option is neodymium disc magnets. Glue a magnet to the back of the item you want to affix to the wall, then hold another magnet on the outside of the wall (exterior of the house) until they pull together. You can glue more (or bigger) magnets to hang heavier items.