When we buy a classic camera, one of the things that almost certainly will need to be replaced are the light seals.
These seals are foam placed over 40 or 50 years ago and it deteriorated with time, became a sticky and no longer fulfills its function, that is to prevent light from entering the compartment where the film is located.
And it is absolutely necessary, if you want to use your camera, to replace.
And it is a work of patience.
The work begins with the removal of old foam.
To start if you want to do for yourself will need:
Cotton swabs, toothpicks, alcohol and paper towels
And of course the seals that are for sale on eBay on cut sheets with various thicknesses and then have to cut as according to your camera.
Here is a link where you can find usefull resources for to do this kinf of work:
If you find to hard, you can ask for a shop to do it, but remember its important to replace, otherwise you will have pictures burned caused by light.