About 6 years agoI lived in an apartment complex and was able to
listen to many phone conversations. I used a telescoping whip on my
scanner (about $10 from RS).

Scan 46-47 mhz, 49-50mhz, & 900-920mhz

Good luck! (I lost interest in listening to cordless calls when they
became mostly foreign languages), but I did hear some nice phone sex
conversations.

Since you say you live in a complex, I would use headphones.