3 yr old Night Waking

Does anyone have any suggestions for night waking?  Turkey has started getting up in the middle of the night recently.  It started at Nana’s house so we thought it might be that he didn’t want to miss any play time with her.  Then it carried over to his MeMee and Pa’s house.  He says he hears things.  We live in an apartment complex for goodness sakes- he should be used to hearing anything and everything.  We’ve been home 4 nights and I think he’s awoken in the middle of the night at least 3 of them.  We’ve never dealt with this from any of our kids for more than a night or two when they were sick.  I’d appreciate any ideas anyone can offer.