Water leekage in basement bathroom

In our downstairs bathroom there has been a water leekage from the shower cabinet (probably for years). It is occupied by a tenant. We now have issues with bugs. We need to check wall for water damage, and change lists (both sides of wall) and fix shower cabinet. a potential solution: - check if wall is okey - change lists in bathroom an most likely in kitchen. Consider solution with plastic and not wood, using tec7 - consider if leekage in cabinet can be fixed with silicon (or similar) or if we need to buy new need fix within 7 days