Read High voltage from PIC16F
No, you usually can't read a voltage higher than the supply voltage of your microcontroller. To know exactly the maximum voltage that your microcontroller can read you need to look in the datasheet. You can use a voltage divider made of two resistors so that your microcontroller can safely read the voltage.

Here are its design equations:

$$
\begin{split}
&amp;\frac{V_\mathrm{in}} {Z1 + Z2} \cdot Z_2 = V_\mathrm{out}\\
\\
&amp;\frac{(V_\mathrm{in} - V_\mathrm{out})^2}{Z_1} =\text{ Power dissipated by }Z_1
\end{split}
$$

I suggest choosing \$Z_1\$ first.





If it's AC you'll need something else.

Be careful with high voltage. If you're not sure what you're doing, don't do it.