One of the electric light switches in my mother's house makes a squeak/squeal noise when it's turned on and off. The pitch of the noise is slightly different depending on whether it's being turned on or off. The house is very old- over 100 yrs- and I'm not sure when would have been the last time electrical work was done. I don't live with my mother- she lives alone- and I noticed this on my last visit home. I'm concerned this may become a fire hazard. Should I call an electrician to look at it? Thank you!

The switch is probably worn out. It could be a single or double pole switch. If it says ON and OFF it is a single pole and if it says nothing, it is a 3 way switch. Normally you turn off the breaker or fuse, remove the switch, disconnect the wires and reconnect in the same pattern. Although they are not hard to change, if you don't feel confident, call an electrician or find a referred handy man. Switches rarely cause fires, outlets are much more common as a fire source.

A word of caution, a house this old may still have know and tube wiring or at the least paper wrapped cables.

The insulation on the cabling needs to be checked to make sure it is still safe.

The light socket in my garage appears to be squeaky, and perhaps a little rusty-like residue appears on the socket. Right now it is not making a connection, and I am thinking this is the reason why. Is there an easy solution I can try before replacing the socket? I am not into fixing my own electrical items, so I would have to pay someone. Just don't want to do it unless it is really needed.
Thanks in advance!