Always someone with a landlines in a village. I believe some had telephone boxes too.
You can bet the local Amphur and Pu Yai had a phone.
"The penetration of telephone remained relatively limited for most of the 20th century. In 1992, the ratio of telephone lines per population was 3.3 lines per 100 population. In 1991, two private corporations were given concessions to build and operate telephone lines: Telecom-Asia (later renamed True Corporation) for the Bangkok Metropolitan Region and Thai Telephone & Telecommunications (TT&T) for the provinces.[5]"
As of 2014, there were 97.6 million mobile subscribers in Thailand, a penetration rate of 146 percent of the total population.