How to detect rouge AP?

I found the wifi experience is very bad in my environment, the loss of packets is very serious, and I always cannot connect to the wifi signal,
I suspect there is a rouge ap in my environment,
what should I check ?

You can use a professional tool (Ominpeek) to capture packets in your environment. If there is a great amount of deauthentication (Deauth) packets, it shows that maybe there is a rouge ap exists.
you need to check your surrounding environment, if there is a different vendor ap and its led flash very fastly, you can power off it first, then check again. if your experience become better, and after power on this ap, your experience becaome worse again. it means this ap is the root cause.