Just to put one matter straight, whatever you have been told the absence of earthing does not in itself invite an accident, but if one happens (due to the connection of a faulty electrical item, abuse of sockets, etc.) then the absence of an earth connection removes a fail-safe feature - but earthing is not meant to be constantly required for electrical items to function correctly and safely. Two pin plugged items don't even connect to earth and many items with a three pin plug have a "false" earth pin that has no connection built in, all quite legal and accepted. If an accident is assumed to be inevitable then that is based on an assumption that the place is heaving with unsafe equipment and reckless people. That said, earthing is definitely supposed to be in place for three pin sockets in the UK to be as intended (abroad two pin earthed perform precisely the same function). A landlord's gas safety certificate is a legal requirement and the tenant is supposed to be able to see it on demand - it is to be renewed annually. I am unclear as to how the local council can take out proceedings against a landlord unless it is because the rent agreement somehow involves the council (say, some sort of benefit connection) but then I am not knowledgeable about legal aspects in this area - perhaps the council is empowered to act like a policing authority when they disapprove of some operator. But your sister has always had the choice to leave, although any affordable alternative may have been even less palatable. I understand there are bodies that try to mediate between tenant and landlord to sort out grievances, perhaps that is an option, check with Citizens Advice or Consumer Direct. If your sister wants to stay where she is then it is not in her interest to be wildly confrontational and risk being expelled - her landlord is likely to have the right to put her out with at most two months' notice and get court assistance to forcibly remove her if necessary.