What would you do if u came across a phone that wasn't yours?!!?

kk-so today i lost my phone. it is in either 2 places of my h.s. if u came across it would you keep it, return it to the office, call the home #, or etc. now my mom blocked all calls when she found out that i lost it. this is just for me to find out if i should be afraid of neva findin it teell the truthh peopss! byeya! xo-xo gossip girl......