Ex Landlord he will be here at 9am help plz

So my landlord sold the house now we have a new landlord all good now the ex landlord said he is dropping something off to me but Idk what it could be cause my sister lives in the one apartment behind me and she didn't get his text. So it's not a security deposit. Long story short I had asked ex landlord before he sold it if he could figure out why my electric bill is so high for a 2br apt that's maybe 800 Sq ft. We figured out the only hot water tank for all four Apts is on my electricity bill. So he said if he owes us money he would pay us back but he decided to sell the house. I know we don't owe him money for past rent or anything so isn't an eviction notice but what else could it be like I'm freaking out a little bit bc I highly dought its a check for the electric. Has anyone else had this happen to them. He said it has to be this week..... I'm freaking out,🙁🤔