Do you need a proper electrician to fit a plug socket cover.?

i live in private rented accomadation, i have only lived here two weeks but when i moved in there were 101 things which needed fixing and replacing. the landlady has sent one of her friends round today to fix some of the problems, one of which is 3 burnt out plug sockets, he said he was going to replace the covers on them. surely if they are burnt out there is a problem with the electrics? is he ven allowed to change the covers if he is unqualified? i dont no im no expert thats why im asking here lol