Perhaps the most widespread of all Chinglish expressions (it has become virtually a standard throughout China) is "slip carefully", with extensions such as "carefully slip and fall down", "please slip carefully", and so forth.
The canonical version of the original Chinese is xiǎoxīn dì huá 小心地滑.
For this, Google Translate and Bing Translator both give "slide carefully", while Baidu Fanyi lists the following:
Caution! Wet Floor
Caution! Slippery/Wet Floor
Caution! Slippery/Caution! Wet Floor
Be careful of landslide
The most common variant of the original is xiǎoxīn huá dǎo 小心滑倒.
Watch your step
Caution! Wet Floor/ Caution! Slippery
Brendan O'Kane sent in the following, which helps to explain how the mistranslation of the first version came about:
My younger brother's band Goitse — pronounced "GwITCH-uh;" basically the Donegal Irish dialect word for "Yo" — toured China for seven weeks this past winter, and returned with plans to call a set of slip-jigs on their forthcoming album "Slip Carefully," from the near-ubiquitous mistranslation of "小心地滑."
The album's now out — I'm listening to it now — and it just occurred to me that "Slip Carefully," which is probably at least as common in English signage as the correct translation, is almost certainly a perfect example of Chinglish via machine translation: it makes absolutely perfect sense if you're scanning forward through the string and are in the habit of treating 地 as an adverbial marker when it comes between an adjective and a verb, but is not the kind of mistake that any human would make.
As for the second version, xiǎoxīn huá dǎo 小心滑倒, a literal translation of the components yields:
xiǎoxīn 小心 ("careful")
huá 滑 ("slip; slide")
dǎo 倒 ("fall over")
where dǎo 倒 is a resultative complement of the verb huá 滑. Hence, "be careful not to slip and fall", "be careful lest you slip and fall", etc.