Dialectal interference in Shanghai

Here's a photo of a warehouse on Chongming Island, at the northern edge of Shanghai, which deals in various agricultural products, as listed on the two signs:

(Source)

At the top of the large blue sign above the door, it reads:

běn cǐ jīngyíng 本此经营 ("this here deals in"), where cǐ 此 ("here") is an erroneous character

At the top of the white sign to the right of the door, it reads:

běn chù jīngyíng xiàngmù 本处经营项目 ("this place deals in [these] items"), where chù 处 is the correct usage

In Wu topolect, to which Shanghainese belongs, the following pronunciations pertain:

此 tshr (T2); Middle Sinitic /t͡sʰiᴇ^X/

处 tshr (T2); Middle Sinitic /t͡ɕʰɨʌ^X/

Thus we can see that the pronunciation of 此 and 处 in modern Wu is identical, which would have led to the confusion between the two characters on the blue and white signs.

[Thanks to Joel Martinsen]