(host) #ap-leds ap-name AP125 blink
(host) #ap-leds ap-name AP125 normal
If you have a smartphone app like wifianalyzer, it will tell you the bssid, but not the AP-name that you are seeing the signal strength of. To show the AP that you are standing under do this:
(host) # show ap bss-table | include 00:1a:1e:20:82:e2
00:1a:1e:20:82:e2 Guest 1/3 192.168.1.251 g-HT ap 11/20.5/20.5 0 AP125 0 1d:4h:17m:11s 1500 - 65 T
The AP name connected to that bssid is "AP125". You can just put the last 4 digits of the mac address with a colon between them (case sensitive) and it will give you the same output.