Is this safe?

I had a radiator pipe leak recently and a plumber came around today to sort it out. Days before the electrics upstairs lights kept tripping the fuse box labeled as “lights” every time I turned it back on it’ll shut back off. My landlord kept trying to downplay everything and told me it was a faulty light bulb, even thought it was my bedroom light, kids bedroom light and bathroom light. Going back to this situation now, when the plumber came today he found this when he opened the floor to look for the leak. This is in my children’s room and I’m beginning to think this is why it was tripping? Is this safe?

I had a radiator pipe leak recently and a plumber came around today to sort it out. Days before the electrics upstairs lights kept tripping the fuse box labeled as “lights” every time I turned it back on it’ll shut back off. My landlord kept trying to downplay everything and told me it was a faulty light bulb, even thought it was my bedroom light, kids bedroom light and bathroom light. Going back to this situation now, when the plumber came today he found this when he opened the floor to look for the leak. This is in my children’s room and I’m beginning to think this is why it was tripping? Is this safe?