found by someone in the bathroom on the wall
It says, "For a good time, call . . . "
Seriously, could you take a better photo? I just realized there appear to be one or two other strokes (I first saw seven) that I didn't see the first 10 times I looked at this. A better photo might reveal it to be more than one character. At present it comes closest to an archaic character that I can type but then does not display after I save my post (ㄐ|ㄝˋ ; means big), but it isn't that.
This does not look like oracles bones to me. It looks like lesser seal script (小篆) or maybe Warring States script (戰國文字). But I can't find a match for it as the top three strokes don't form anything familiar to me. It could very easily be that the person who wrote it wrote it wrong, whether consciously or not. It could very easily be that I don't know this character.
As I have noted elsewhere on the board, Chinese people are not 'native speakers' of Chinese characters. Even for modern standard forms in Taiwan or the PRC it is not uncommon for highly educated people to get things wrong. For older forms of the script, native speakers/native readers almost never know much of anything about it. I have had professional CSL teachers tell me all sorts of nonsense about Chinese characters, and more of that from others with loads of formal education in subjects not specific to the history of Chinese characters.