i received money 5000 PKR but don't know who sent and no call or text received asking for that it is mistakenly sent to you. Is this money halal for me or not I waited 1 week almost but no one asked me for money it is still in my account safe and sound. should i spend it or not? what should i Do?
Brother, in my humblest opinion the best solution is to spend this amount in charity/Sadaqa if you are not in dire need of the money.
As RasulAllah S.A.W said,
I heard Allah's Messenger (ﷺ) saying, 'Both legal and illegal things are evident but in between them there are doubtful (suspicious) things and most of the people have no knowledge about them. So whoever saves himself from these suspicious things saves his religion and his honor. And whoever indulges in these suspicious things is like a shepherd who grazes (his animals) near the Hima (private pasture) of someone else and at any moment he is liable to get in it. (O people!) Beware! Every king has a Hima and the Hima of Allah on the earth is His illegal (forbidden) things. Beware! There is a piece of flesh in the body if it becomes good (reformed) the whole body becomes good but if it gets spoilt the whole body gets spoilt and that is the heart.
~ Sahih Bukhari (Hadith 52)
In the context of lost things, it is recommended by the Prophet S.A.W to publically announce it for 2-3 years and if the owner still doesn't come to retrieve it, then you can utilize it. However the case here is somewhat different, you can't publically announce it, and it surely wasn't lost, more like a mistake by the original sender.
Try keeping it for another week or two and if no one contacts you, better to give Sadaqa.